A 25 kg rock resting on the bottom of a lake must be moved from the paths of boats. The rock has a density of 2350 kg/m^3. What force is needed to lift the rock while under water?

Answers

Answer 1

Answer:

The force needed is the weight of the rock minus the buoyant force.

Explanation:


Related Questions

Which term defines the distance from crest to crest

Answers

Answer:

The horizontal distance between two adjacent crests or troughs is known as the wavelength.

Answer: Wavelength

Explanation:

From crest to crest, it is one full wavelength

Under electrostatic conditions, the electric field just outside the surface of any charged conductor

A. is always zero because the electric field is zero inside conductors
B. can have non zero components perpendicular to and parallel to the surface of the conductor
C. is always perpendicular to the surface of the conductor
D. is always parallel to the surface
E. is perpendicular to the surface of the conductor only if it is a sphere, a cylinder, or a flat sheet.

Answers

Answer:

C. is always perpendicular to the surface of the conductor

Explanation:

On a charged conductor , electric charge is uniformly distributed on its surface . The lines of forces are also uniformly  distributed on all directions . They repel each other so they emerge perpendicular to the surface so that they do nor cut each other and at the same time they remain at maximum distance from each other.

You would like to know whether silicon will float in mercury and you know that can determine this based on their densities. Unfortunately, you have the density of mercury in units of kilogram-meter^3 and the density of silicon in other units: 2.33 gram-centimeter^3. You decide to convert the density of silicon into units of kilogram-meter^3 to perform the comparison.
By which combination of conversion factors will you multiply 2.33 gram-centimeter^3 to perform the unit conversion?

Answers

Answer:

Explanation:

To convert gram / centimeter³ to kg / m³

gram / centimeter³

= 10⁻³ kg / centimeter³

= 10⁻³  / (10⁻²)³ kg / m³

= 10⁻³ / 10⁻⁶ kg / m³

= 10⁻³⁺⁶ kg / m³

= 10³ kg / m³

So we shall have to multiply be 10³ with amount in gm / cm³ to convert it into kg/m³

2.33 gram / cm³

= 2.33 x 10³ kg / m³ .

Photons of light scatter off molecules, and the distance you can see through a gas is proportional to the mean free path of photons through the gas. Photons are not gas molecules, so the mean free path of a photon is not equal to that of a molecule, but its dependence on the number density of the gas and on molecular radius is the same. Suppose you are in a smoggy city and can barely see buildings 500 m away.
(a) How far would you be able to see if all the molecules around you suddenly doubled in volume?
(b) How far would you be able to see if the temperature suddenly rose from 20◦C to a blazing hot 1500◦C with the pressure unchanged?

Answers

Answer:

a) 315 m

b) 3025.6 m

Explanation:

The picture attached shows the full explanation for the problem.

You expend 1000 W of power in moving a piano 5 meters in 5 seconds. How much force did you exert?

Answers

Answer:B

Explanation:

Power=1000 watts

Time=5 seconds

Distance=5 meters

Force=(power x time) ➗ distance

Force=(1000 x 5) ➗ 5

Force=5000 ➗ 5

Force=1000

Force=1000N

Answer:1,000

Explanation:

ape.x

Distributions of electric charges in a cell play a role in moving ions into and out of a cell. In this situation, the motion of the ion is affected by two forces: the electric force due to the non-uniform charge distribution in the cell membrane, and the resistive force (viscosity) due to colliding with the fluid molecules. In order to begin our analysis of this, let's consider a toy model in which the ion is moving in response to electric forces alone.

Charges in a cell membrane are distributed along the opposite sides of the membrane approximately uniformly. This leads to an (on the average) constant electric field inside the membrane. A simple model that gives this kind of field is two large parallel plates close together. The field between the plates is approximately constant pointing from the negative to the parallel plate. This results in a charge feeling a constant force anywhere between the plates (sort of like flat-earth gravity turned sideways). Outside of the plates the electric fields from the two plates cancel and there is no force.

2. The electric field between the plates (inside the membrane) is about 107 N/C and the thickness of the membrane is about 7 nm. Estimate:

2.1 The electric force on the ion when it is in the center of the channel.
F = N

Explain your reasoning.



2.2 The acceleration of the ion when it is in the center of the channel.
a = nm/s2
Explain your reasoning.



2.3 The magnitude of the change in the ion's potential energy as it crosses from one side of the plates to the other.
U = J
Explain your reasoning.



2.4 The kinetic energy the ion would gain as it crosses from one side of the plates to the other.
KE = J
Explain your reasoning.

Could you explain 2.3!

Answers

Answer:

An atom is the smallest constituent unit of ordinary matter that constitutes a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small; typical sizes are around 100 picometers.Explanation:

An atom is the smallest constituent unit of ordinary matter that constitutes a chemical element.

What is atom?

Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small; typical sizes are around 100 picometers.

Each atom is made up of a nucleus and one or more electrons that are linked to it. One or more protons and a significant number of neutrons make up the nucleus. Only the most prevalent type of hydrogen is neutron-free.

Atoms that are neutral or ionized make up every solid, liquid, gas, and form of plasma. Atoms are incredibly tiny, measuring typically 100 picometers across. The nucleus of an atom contains more than 99.94% of its mass.

Therefore, An atom is the smallest constituent unit of ordinary matter that constitutes a chemical element.

To learn more about atom, refer to the link:

https://brainly.com/question/1566330

#SPJ2

Two forces are applied on a body. One produces a force of 480-N directly forward while the other gives a 513-N force at 32.4-degrees above the forward direction .Find the magnitude and direction(relative to forward direction of the resultant force that these forces exert on the body)​

Answers

Answer:

F = (913.14 , 274.87 )

|F| = 953.61 direction 16.71°

Explanation:

To calculate the resultant force you take into account both x and y component of the implied forces:

[tex]\Sigma F_x=480N+513Ncos(32.4\°)=913.14N\\\\\Sigma F_y=513sin(32.4\°)=274.87N[/tex]

Thus, the net force over the body is:

[tex]F=(913.14N)\hat{i}+(274.87N)\hat{j}[/tex]

Next, you calculate the magnitude of the force:

[tex]F=\sqrt{(913.14N)+(274.87N)^2}=953.61N[/tex]

and the direction is:

[tex]\theta=tan^{-1}(\frac{274.14N}{913.14N})=16.71\°[/tex]

why are brother anoying

Answers

Answer:

because they want attention, and big brother loves his younger one

Explanation:

A 3.6 kg block moving with a velocity of 4.3 m/s makes an elastic collision with a stationary block of mass 2.1 kg.

(a) Use conservation of momentum and the fact that the relative speed of recession equals the relative speed of approach to find the velocity of each block after the collision. 1.1315 m/s (for the 3.6 kg block) 5.43 m/s (for the 2.1 kg block)

(b) Check your answer by calculating the initial and final kinetic energies of each block. 33.282 J (initially for the 3.6 kg block) J (initially for the 2.1 kg block) J (finally for the 3.6 kg block) J (finally for the 2.1 kg block) Are the two total kinetic energies the same?

Answers

Answer:

a) Velocity of the block of mass 3.6 kg after collision = 1.13 m/s

Velocity of the block of mass 2.1 kg after collision = 5.43 m/s

b) Initial energy of the 3.6 kg block = 33.282 J

Final energy of the 3.6 kg block = 2.3 J

Initial energy of the 2.1 kg block = 0J

Final energy of the 2.1 kg block = 30.96 J

The two total kinetic energies are the same = 33.30 J

Explanation:

Check the attached files for the complete solution and explanations.

A car speeds up from 18.54 m/s to
29.52 m/s in 13.84 s.
The acceleration of the car is:

Answers

Answer:

.7934[tex]m/s^{2}[/tex]

Explanation:

Acceleration = change in velocity / change in time

A = 10.98[tex]m/s[/tex] / 13.84[tex]s[/tex]

A = .7934[tex]m/s^{2}[/tex]

Answer:0.8 m/s^2

Explanation:

initial velocity(u)=18.54m/s

Final velocity(v)=29.52m/s

Time(t)=13.84 sec

Acceleration =(v-u)/t

acceleration =(29.52-18.54)/13.84

Acceleration =10.98/13.34

Acceleration=0.8 m/s^2

a) When we were examining the Electromagnetic Tab, we saw that a flow of electrons or a current as we say it, creates a magnetic field. What about the converse, can a magnetic field be involved in the creation of a flow of electrons/current? Therefore is it reasonable to suggest that we can create a magnetic field by having a flow of current and this can be used to make more current? Explain how this can occur

Answers

Answer:

Magnetic field can be used to produce current, infact a changing magnetic field can produce current.

A changing magnetic field in a loop causes the flux linked with the loop to change in turn generating a emf in the loop and therefore a current.

For a loop of area A and resistance R.

I =dPhi/dt/R

В. А

I = AcosФ/R .dB /dt

But it isn't reasonable to say that we can create a magnetic field by having a flow of current and this can be used to make more current because the current generated due to change in magnetic field created by increase/decrease in flow of current will be in a direction such that it will counter act the change in magnetic field caused by increase/decrease in current flow.(lenz's law).

We were unable to transcribe this image

Ф= В. А

I = Acos dB Rd

Pendulum clock. Your friend is trying to construct a clock for a craft show and asks you for some advice. She has decided to construct the clock with a pendulum. The pendulum will be a very thin, very light wooden bar with a thin, but heavy, brass ring fastened to one end. The length of the rod is 80 cm and the diameter of the ring is 10 cm. She is planning to drill a hole in the bar to place the axis of rotation 15 cm from one end. She wants you to tell her the period of this pendulum.

Answers

Answer:

The time period for this pendulum is 1.68 seconds

Explanation:

Solution

Given that:

The length of the pendulum is measured from the axis of rotation to the center of mass of the bob of the pendulum

Now,

In this case, the length becomes:

L= 80 - 15+5

L = 70 cm

The time period = T = 2π √L/g

T = 2* 3.14 *√0.7/9.8

= 1.68 seconds

Note: Kindly find an attached work to the part of the solution of the given question

An ideal spring is fixed at one end. A variable force F pulls on the spring. When the magnitude of F reaches a value of 30.8 N, the spring is stretched by 17.7 cm from its equilibrium length. Calculate the additional work required by F to stretch the spring by an additional 12.4 cm from that position.

Answers

Answer:

[tex]W=5.16 J[/tex]  

Explanation:

Using the Hooke's law we can find the elasticity constant:

[tex]F=-k\Delta x[/tex]

[tex]30.8=-k*0.177[/tex]

[tex]k=|-\frac{30.8}{0.177}|[/tex]

[tex]k=174 N/m[/tex]

Now, we know that the work done is equal to the elastic energy, so we will have:

[tex]W=\frac{1}{2}k(x_{2}^{2}-x_{1}^{2})[/tex]

x2 is the final distance (x2 = 0.177+0.124 = 0.301 m)

x1 is the initial distance (x1 = 0.177 m)

[tex]W=\frac{1}{2}*174(0.301^{2}-0.177^{2})[/tex]

[tex]W=5.16 J[/tex]    

I hope it helps you!

Which of these parameters is directly related to sound frequency?

Answers

Answer:Velocity

Explanation:

Velocity is directly proportional to the frequency of a wave.

Velocity=frequency x wavelength

Mr. Dunn drives 64.8km from work at a speed of 48km/h. Mrs. Dunn drives 81.2km from work
at a speed of 58km/h. They both leave work at the same time. Show complete working to secure
full credits. [4]
i. Who arrives home first?
ii. How many minutes later is it before the second person gets home?
iii. A Coyote is chasing its meal (the Road Runner). Unfortunately, the Coyote has difficulty
adjusting to the Road Runner’s speed but we have a good idea of what it is.
plz help me i will mark you as brainliest

Answers

Answer:

i) Mr. Dunn arrives to home first.

ii) 3 min

Explanation:

i. To find who arrives first to home you calculate the time, by using the following formula:

[tex]t=\frac{x}{v}[/tex]

x: distance

v: velocity

Mr. Dunn:

[tex]t=\frac{64.8km}{48km/h}=1.35h[/tex]

Mrs. Dunn:

[tex]t=\frac{81.2km}{58km/h}=1.4h[/tex]

Hence, Mr. Dunn arrives to home first.

ii. To calculate the difference in minutes, you convert hours to minutes:

[tex]1.35h*\frac{60min}{1h}=81min\\\\1.40h*\frac{60min}{1h}=84min\\\\\Delta\ t=(84-81)min=3min[/tex]

the difference between the times is 3min

(i) Mr. Dunn takes less time so he arrives at home first.

(ii) The second person arrives 3 min late.

Time taken to arrive home:

(i) We have to calculate the time taken to reach home by Mr. Dunn and Mrs. Dunn.

t = x/v

where x is the distance

and v is the velocity

Time taken by Mr. Dunn:

distance x = 64.8 km

speed v  = 48 km/h

t = 64.8 / 48

t = 1.35 h

Time taken by Mrs. Dunn:

distance x = 81.2 km

speed v  = 58 km/h

t' = 81.2 / 58

t' = 1.4 h

Hence, Mr. Dunn arrives at home first.

(ii) To calculate the difference in minutes, you convert hours to minutes:

The time taken by Mr. Dunn in minutes is:

t = 1.35×60 = 81 minutes

The time taken by Mrs. Dunn in minutes is:

t' = 1.4×60 = 84 minutes

the difference between the times is 3min

Learn more about distance and time :

https://brainly.com/question/4199102?referrer=searchResults

The uniform slender bar of mass m and length l is released from rest in the vertical position and pivots on its square end about the corner at O. (a) If the bar is observed to slip when   30 , find the coefficient of static friction s between the bar and the corner. (b)If the end of the bar is notched so that it cannot slip, find the angle  at which contact between the bar and the corner ceases.

Answers

Answer:

A) 0.188

B) 53.1 ⁰

Explanation:

taking moment about 0

∑ Mo = Lo∝

mg 1/2 sin∅ = 1/3 m L^2∝

note ∝ = w[tex]\frac{dw}{d}[/tex]∅

forces acting along t-direction ( ASSUMED t direction)

∑ Ft = Ma(t) = mr∝

mg sin ∅ - F = m* 1/2 * 3g/2l sin∅

therefore F = mg/4 sin∅

forces acting along n - direction ( ASSUMED n direction)

∑ Fn = ma(n) = mr([tex]w^{2}[/tex])

= mg cos∅ - N = m*1/2*3g/1 ( 1 - cos∅ )

hence N = mg/2 ( 5cos∅ -3 )

A ) Angle given = 30⁰c find coefficient of static friction

∪ = F/N

  = [tex]\frac{\frac{mg}{4}sin30 }{\frac{mg}{2}(5cos30 -3) }[/tex]  = 0.188

B) when there is no slip

N = O

   = 5 cos ∅ -3 =0

   therefore cos ∅ = 3/5  hence ∅ = 53.1⁰

The friends now feel prepared for a homework problem. Consider a cylinder initially filled with 9.30 10-4 m3 of ideal gas at atmospheric pressure. An external force is applied to slowly compress the gas at constant temperature to 1/6 of its initial volume. Calculate the work that is done. Note that atmospheric pressure is 1.013 105 Pa

Answers

Answer:

Explanation:

Initial volume of gas V₁ = 9.30 x 10⁻⁴ m³

final volume V₂ = 1 / 6 x  9.30 x 10⁻⁴

= 1.55 x 10⁻⁴ m³

Atmospheric pressure P = 1.013 x 10⁵ Pa .

temperature T .

PV = n RT

nRT = 1.013 x 10⁵ x 9.3 x 10⁻⁴

= 94.21

work done in isothermal process

= 2.303 nRT log V₁ / V₂

= 2.303 x 94.21 log 6

= 168.83 J .

The current in the wires of a circuit is 60 milliamps. If the resistance of the circuit were doubled (with no change in voltage), then it’s new current would be _____ milliamps

Answers

Answer:30

Explanation:

Current=60 milliamps

Current=(voltage)/(resistance)

60=(voltage)/(resistance)

Doubling the resistance means multiplying both sides by 1/2

60x1/2=(voltage)/(resistance) x 1/2

30=(voltage)/2(resistance)

Therefore the resistance would be 30 milliamp if we double the resistance

An astronaut is being tested in a centrifuge. The centrifuge has a radius of 11.0 m and, in starting, rotates according to θ = 0.260t2, where t is in seconds and θ is in radians. When t = 2.40 s, what are the magnitudes of the astronaut's (a) angular velocity, (b) linear velocity, (c) tangential acceleration, and (d) radial acceleration?

Answers

Answer:

a) 1.248 rad/s

b) 13.728 m/s

c) 0.52 rad/s^2

d) 17.132m/s^2

Explanation:

You have that the angles described by a astronaut is given by:

[tex]\theta=0.260t^2[/tex]

(a) To find the angular velocity of the astronaut you use the derivative og the angle respect to time:

[tex]\omega=\frac{d\theta}{dt}=\frac{d}{dt}[0.260t^2]=0.52t[/tex]

Then, you evaluate for t=2.40 s:

[tex]\omega=0.52(2.40)=1.248\frac{rad}{s}[/tex]

(b) The linear velocity is calculated by using the following formula:

[tex]v=\omega r[/tex]

r: radius if the trajectory of the astronaut = 11.0m

You replace r and w and obtain:

[tex]v=(1.248\frac{rad}{s})(11.0m)=13.728\frac{m}{s}[/tex]

(c) The tangential acceleration is:

[tex]a_T=\alpha r\\\\\alpha=\frac{\omega^2}{2\theta}=\frac{(1.248rad/s)^2}{2(0.260(2.40s)^2)}=0.52\frac{rad}{s^2}[/tex]

(d) The radial acceleration is:

[tex]a_r=\frac{v^2}{r}=\frac{(13.728m/s)^2}{11.0m}=17.132\frac{m}{s^2}[/tex]

In a shipping company distribution center, an open cart of mass 50 kg is rolling to the left at a speed of 5 m/s. You can ignore friction between the cart and the floor. A 15 kg package slides down a chute that makes an angle of 27 degrees below the horizontal. The package leaves the chute with a speed of 3 m/s, and lands in the cart after falling for 0.75 seconds. The package comes to a stop in the cart after 4 seconds. What is:a) the speed of the package just before it lands in the cart

Answers

Answer:

Explanation:

The package leaves the chute with a speed of 3 m/s, and lands in the cart after falling for 0.75 seconds . During .75 second duration . package undergoes free fall due to which additional vertical velocity is added

velocity added = a x t

= 9.8 x .75

= 7.35 m /s

Total vertical velocity

= 3 sin27 + 7.35

= 8.71 m /s

Horizontal component = 3 cos 27

= 2.67 m /s

If v be the resultant velocity of these components

v² = 2.67² + 8.71²

v² = 7.13 + 75.86

v = 9.11 m /s .

Coulomb's law for the magnitude of the force FFF between two particles with charges QQQ and Q′Q′Q^\prime separated by a distance ddd is


|F|=K|QQ′|d2|F|=K|QQ′|d2,


where K=14πϵ0K=14πϵ0, and ϵ0=8.854×10−12C2/(N⋅m2)ϵ0=8.854×10−12C2/(N⋅m2) is the permittivity of free space.


Consider two point charges located on the x axis: one charge, q1q1q_1 = -15.0 nCnC , is located at x1x1x_1 = -1.660 mm ; the second charge, q2q2q_2 = 34.5 nCnC , is at the origin (x=0.0000)(x=0.0000).


What is the net force exerted by these two charges on a third charge q3q3q_3 = 47.0 nCnC placed between q1q1q_1 and q2q2q_2 at x3x3x_3 = -1.240 mm ?


Your answer may be positive or negative, depending on the direction of the force.

Answers

Answer:

Explanation:

Force between two charges of q₁ and q₂ at distance d is given by the expression

F = k q₁ q₂ / d₂

Here force between charge q₁ = - 15 x 10⁻⁹ C and q₃ = 47 x 10⁻⁹ C when distance between them d = (1.66 - 1.24 ) = .42 mm

k = 1/ 4π x 8.85 x 10⁻¹²

putting the values in the expression

F = 1/ 4π x 8.85 x 10⁻¹²  x - 15 x 10⁻⁹ x 47 x 10⁻⁹ /( .42 x 10⁻³)²

= 9 x 10⁹ x  - 15 x 10⁻⁹ x 47 x 10⁻⁹ /( .42 x 10⁻³)²

= 35969.4 x 10⁻³ N .

force between charge q₂ =  34.5 x 10⁻⁹ C and q₃ = 47 x 10⁻⁹ C when distance between them d = ( 1.24 - 0 ) = 1.24 mm .

putting the values in the expression

F = 1/ 4π x 8.85 x 10⁻¹²  x  34.5 x 10⁻⁹ x 47 x 10⁻⁹ /( .42 x 10⁻³)²

= 9 x 10⁹ x  - 34.5 x 10⁻⁹ x 47 x 10⁻⁹ /( .42 x 10⁻³)²

= 82729.6  x 10⁻³ N

Both these forces will act in the same direction towards the left (away from the origin towards - ve x axis)

Total force = 118699 x 10⁻³

= 118.7 N.

in the figure calculates the acceleration of the block friction not today

Answers

Answer:

A fan pushes hot air out of a vent and into a room. The hot air displaces cold air in the room, causing the cold air to move closer to the floor.

The hot air displacing the cold air is an example of  transfer by

Explanation:

also the answer is hit my dm on ig

A firearms company is testing a new model of rifle by firing a 7.50-g lead bullet into a block of wood having a mass of 17.5 kg. The bullet embeds into the block and the collision generates heat. As a consequence, the temperature rises by 0.040°C, as measured with a high-precision thermometer. Assuming that all the kinetic energy of the bullet goes into heating the system, what is the bullet’s speed when it enters the block? The initial temperatures of bullet and wooden block can be considered identical and the specific heats of lead and wood are cPb = 130 J/(kg ⋅ C°) and c wood = 1700 J/(kg ⋅ C°), respectively.

Answers

Answer:

Explanation:

Let the bullets speed be V .

Kinetic energy = 1/2 mV² where m is mass of bullet

This energy is converted into heat Q which raises the temperature of target by Δ T .

Q = mc Δ T  , m is mass , c is specific heat and Δ T is rise in temperature .

heat absobed by bullet

= .0075 x 130 x .040

= .039 J

heat absorbed by block of wood

= 17.5 x 1700 x .04

= 1190 J

Total heat absorbed

= 1190.039 J

So kinetic energy = heat absobed

= 1/2 x .0075 x V² = 1190.039

V² = 317343.73

V  = 563.33 m /s

Which element is malleable and ductile

Answers

Answer:

Gold, silver, platinum. Gold is the most malleable and ductile.

Explanation:

The elements which are malleable and ductile include the following:

CopperIronCobalt etc.

What is Malleability and Ductility?

Malleability is the ability of a substance to be hammered into thin sheets

while ductility involves the deformation of a substance without any

breakage occurring in it.

Transition metals are the group of elements which have both

characteristics and examples are listed above.

Read more about Transition metals here https://brainly.com/question/7102290

If A = (6i-8j) units, B = (-8i-3j) units, and C = (26i-19j) units, determine a and b
such that aA + bB + C = 0

Answers

Answer:

Explanation:

given equation

aA + bB + C = 0

Putting the given values

a(6i-8j) +b (-8i-3j) +(26i-19j) = 0

i ( 6a - 8b ) - j ( 8a + 3 b ) = - 26 i + 19 j

comparing the coefficients of i and j

6a - 8b = -26

8a + 3b = -19.

multiplying first equation by 4 and second equation by 3  

24a - 32 b = - 104

24a + 9b = -57

9b + 32b = -57 + 104

41 b = 47

b = 1.41

6 a - 8 x 1.41 = -26

6a = -14.72

a = - 2.45  

An object has a mass of 5 kg. What force is needed to accelerate it at 6 m/s?

Answers

Answer:30N

Explanation:

Mass=5kg

Acceleration=6m/s^2

Force=mass x acceleration

Force=5 x 6

Force=30N

Answer:

30n

Explanation:

Mass=5kg

Acceleration=6m/s^2

Force=mass x acceleration

Force=5 x 6

Force=30N

Official (Closed) - Non Sensitive
MEF Tutorial 2 Q3
A train with a maximum speed of 29.17 m/s has an
acceleration rate of 0.25 m/s2 and a deceleration
rate of 0.7 m/s2. Determine the minimum running
time, if it starts from rest at one station and stops
at the next station 7 km away.​

Answers

Answer:

The minimum running time is 319.47 s.

Explanation:

First we find the distance covered and time taken by the train to reach its maximum speed:

We have:

Initial Speed = Vi = 0 m/s    (Since, train is initially at rest)

Final Speed = Vf = 29.17 m/s

Acceleration = a = 0.25 m/s²

Distance Covered to reach maximum speed = s₁

Time taken to reach maximum speed = t₁

Using 1st equation of motion:

Vf = Vi + at₁

t₁ = (Vf - Vi)/a

t₁ = (29.17 m/s - 0 m/s)/(0.25 m/s²)

t₁ = 116.68 s

Using 2nd equation of motion:

s₁ = (Vi)(t₁) + (0.5)(a)(t₁)²

s₁ = (0 m/s)(116.68 s) + (0.5)(0.25 m/s²)(116.68 s)²

s₁ = 1701.78 m = 1.7 km

Now, we shall calculate the end time and distance covered by train, when it comes to rest on next station.

We have:

Final Speed = Vf = 0 m/s    (Since, train is finally stops)

Initial Speed = Vi = 29.17 m/s     (The train must maintain max. speed for min time)

Deceleration = a = - 0.7 m/s²

Distance Covered to stop = s₂

Time taken to stop = t₂

Using 1st equation of motion:

Vf = Vi + at₂

t₂ = (Vf - Vi)/a

t₂ = (0 m/s - 29.17 m/s)/(- 0.7 m/s²)

t₂ = 41.67 s

Using 2nd equation of motion:

s₂ = (Vi)(t₂) + (0.5)(a)(t₂)²

s₂ = (29.17 m/s)(41.67 s) + (0.5)(- 0.7 m/s²)(41.67 s)²

s₂ = 607.78 m = 0.6 km

Since, we know that the rest of 7 km, the train must maintain the maximum speed to get to the next station in minimum time.

The remaining distance is:

s₃ = 7 km - s₂ - s₁

s₃ = 7 km - 0.6 km - 1.7 km

s₃ = 4.7 km

Now, for uniform speed we use the relation:

s₃ = vt₃

t₃ = s₃/v

t₃ = (4700 m)/(29.17 m/s)

t₃ = 161.12 s

So, the minimum running time will be:

t = t₁ + t₂ + t₃

t = 116.68 s + 41.67 s + 161.12 s

t = 319.47 s

Match these items.


1 . pls help


asteroids

between Mars and Jupiter

2 .

fission

ice, dust, frozen gases

3 .

energy

sun's atmosphere

4 .

fusion

ability to do work

5 .

corona

splitting atoms

6 .

comets

the combining of atomic nuclei to form one nucleus

Answers

Answer:

Here's your answer :

Asteroids - Between mars and JupiterFission - splitting atomsEnergy - Sun's atmosphereFusion - The combining of atomic nuclei to form one nucleusCorona - Ability to do workComets - Ice, dust, frozen gases

hope it helps!

A 25kg box in released on a 27° incline and accelerates down the incline at 0.3 m/s2. Find the friction force impending its motion? What is the coefficient of kinetic friction?
A block is given an initial speed of 3m/s up a 25° incline. Coefficient of friction

Answers

Answer:

a)  μ = 0.475 , b)   μ = 0.433

Explanation:

a) For this exercise of Newton's second law, we create a reference system with the x-axis parallel to the plane and the y-axis perpendicular to it

X axis

     Wₓ - fr = m a

the friction force has the expression

     fr = μ N

y Axis

     N - [tex]W_{y}[/tex] = 0

let's use trigonometry for the components the weight

     sin 27 = Wₓ / W

     Wₓ = W sin 27

     cos 27 = W_{y} / W

     W_{y} = W cos 27

     N = W cos 27

     W sin 27 - μ W cos 27 = m a

     mg sin 27 - μ mg cos 27 = m a

      μ = (g sin 27 - a) / (g cos 27)

      very = tan 27 - a / g sec 27

      μ = 0.510 - 0.0344

      μ = 0.475

b) now the block starts with an initial speed of 3m / s. In Newton's second law velocity does not appear, so this term does not affect the result, the change in slope does affect the result

         μ = tan 25 - 0.3 / 9.8 sec 25

         μ = 0.466 -0.03378

         μ = 0.433

When a high‑energy photon passes near a heavy nucleus, a process known as pair production can occur. As a result, an electron and a positron (the electron's antiparticle) are produced. In one such occurrence, a researcher notes that the electron and positron fly off in opposite directions after being produced, each traveling at speed 0.941c. The researcher records the time that it takes for the electron to travel from one position to another within the detector as 15.7 ns. How much time would it take for the electron to move between the same two positions as measured by an observer moving along with the positron?

Answers

Answer:

1.47*10^{-8}s

Explanation:

You first calculate the distance traveled by the electron:

[tex]x=vt\\\\x=(0.941(3*10^8m/s))(15.7*10^{-9}s)=4.43m[/tex]

Next, you calculate the relative speed as measure by an observer in the positron, of the electron:

[tex]u'=\frac{u+v}{1+\frac{uv}{c^2}}\\\\u'=\frac{0.941c+0.941c}{1+\frac{(0.941)^2c^2}{c^2}}\\\\u'=0.99c[/tex]

with this relative velocity you calculate the time:

[tex]t=\frac{x}{u'}\\\\t=\frac{4.43m}{0.99c}=1.47*10^{-8}s[/tex]

Other Questions
describe the religions found in Ancient Rome what is a unit rate? ASAP WILL GIVE BRAINLIESTThe image below shows how wolves and dogs compare to some other animals in the levels of classification.Based on the chart, how are fish and dogs related? They belong to the same kingdom but different phyla. They belong to the same phylum but different classes. They belong to the same kingdom and class. They belong to the same phylum and class. In middle childhood, teachers and friends play a bigger role in socializing the child thenparentsTrue or false Answer ASAP please A tugboat is pushing a barge in to a harbor.The barge is exerting a force of 3000 N against the tugboat.which force would most likely allow the tugboat to move the barge into the harbor which two technologies use reflected sound waves Which of the following sentences has a connotative meaning? a. "Please do not hassle the customer service representatives with too frequent questions." b. "Your ability to meet deadlines is satisfactory." c. "Research and development has developed an outstanding production process." d. "Rita's drive and enthusiasm make her successful at sales." help will give you brainliest!!! how did the allies deal with the issue of war crimes ineurope Which plant or plant part is a source of edible oils?A.wheatB.kidney beansC.sunflowerD.riceE.cottonseed Amy must choose a number between 55 and 101 that is a multiple of 3, 6, and 7. Write all the numbers that she could choose. If there is more than one number, separate them with commas. Do contact lenses do damage to your eyes? What energy transformations take place in Joule's system? Hawk-Dove (or Chicken) (t = tough, c = concede) Two (young) players are engaged in a conflict situation. For instance, they may be racing their cars towards each other on Main Street, while being egged on by their many friends. If player 1 hangs tough and stays in the center of the road while the other player concedeschickens outby moving out of the way, then all glory is his and the other player eats humble pie. If they both hang tough they end up with broken bones, while if they both concede they have their bodiesbut not their prideintact. Player 1 \ Player 2 t c t -1,-1 10,0 c 0, 10 5, 5 The matrix form can be used to compactly represent the strategic form when there are two players even if each player has more than two strategies to choose from. The shock from an electric fence would be the least unpleasant if you werestandingA. on dry, thick gravelB. in tall grassC. In wet grassOD. near the livestock What happens to light energy that is not absorbed by an object What happens to light energy that is not absorbed by an object Meiji leaders did all of the following excepta.instituted a constitutional monarchyc.modernized the army and navyb.introduced communism as the new social systemd.opened schoolsPlease select the best answer from the choices providedABCD The hourly wages earned by 20 employees are shown in the first box-and-whisker plot below. The person earning $15 per hour quits and is replaced with a person earning $8 per hour. The graph of the resulting salaries is shown in plot 2. A box-and-whisker plot is shown. The number line goes from 7 to 15. The whiskers range from 8 to 15, and the box ranges from 8.8 to 10.2. A line divides the box at 9.5. Plot 1 A box-and-whisker plot is shown. The number line goes from 7 to 15. The whiskers range from 8 to 11, and the box ranges from 8.7 to 10. A line divides the box at 9.6. Plot 2 How does the mean and median change from plot 1 to plot 2? The mean and median remain the same. The mean decreases, and the median remains the same. The mean remains the same, and the median decreases. The mean and median decrease. pls help (ASASP)This is the simplest invertebrate animal. Most are asymmetrical and reproduce either through asexual means or through internal, self-fertilization because most are hermaphrodites. Circle the correct possessive adjective. 1 This handbag belongs to my mother. It's his / her / your handbag.