Need help finding the average speed.

Explanation:

Hello there!!!

You just need to use simple formula for force and momentum,

F= m.a

and momentum (p)= m.v

where m= mass

v= velocity.

a= acceleration .

And the solutions are in pictures.

Hope it helps..

Answer:

True

Explanation:

The average kinetic energy is the measure of how freely the molecules of a substance moves relative to the other molecules within the substance. Gas and liquids are together termed fluids,  but the molecules of a gas naturally has more more average kinetic energy that that of a liquid, if they are kept at the same temperature. This explains why gases are easy to expand, and have to be confined by a container. So the particles of a gas has more kinetic energy that that of a liquid even if they are kept at the same temperature.

Answer:

5.3333 sec

Explanation:

initial speed: u = 108km/hr or 30 m/s

final speed: v = 0m/s

distance travelled: s = 80m

time the car took to stop: = t sec

[tex]v^{2} - u^{2}[/tex] = 2as,

a = ([tex]v^{2} - u^{2}[/tex])/2s

a = (0-900)/160

a = -5.625 [tex]ms^{-2}[/tex]

v = u + at,

t = (v - u)/a

t= (0 - 30)/(-5.625)

t = 5.3333 sec

Answer: A) an upward force balances the downward force of gravity on the skydiver

Explanation: I got it correct on my test on edge

The statement best applies Newton’s laws of motion to explain the skydiver’s motion an upward force balances the downward force of gravity on the skydiver. Thus, option A is correct.

The statement that best applies Newton’s laws of motion to explain the skydiver’s motion is that an upward force balances the downward force of gravity on the skydiver. Newton's 3rd law often applies to skydiving.

When gravity is not acting upon the skydivers they would continue moving in the direction the vehicle they jumped from was moving. If no air resistance takes place, then the skydivers would still accelerating at 9.8 m/s until they hit the ground.

The skydiver after leaving the aircraft will accelerates downwards due to the force of gravity usually as there is no air resistance acting in the upwards direction, and there is a resultant force acting downwards, the skydiver will accelerates towards the ground.

Therefore, The statement best applies Newton’s laws of motion to explain the skydiver’s motion an upward force balances the downward force of gravity on the skydiver. Thus, option A is correct.

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Answer:

Matter can be identified through its properties. One clue to helps us identify matter is magnetism. Magnetism is the ability of a material to be attracted by a magnet. Only certain materials are attracted to magnets, like iron, nickel, and cobalt.

Explanation:

we can identify matter by:  physical properties  and

chemical properties

Answer:

pull

Explanation:

because when you push there is one component of force that adds to tge weight of body and hence there is more friction. Whwn you pull the vertical component of force is against the weight of body and hence friction is low.

Answer:

the focal length of the mirror is :  [tex]f=-2.5\,\,cm[/tex]

Explanation:

Use the formula for the formation of image using a divergent mirror and recalling that the image (s') that this mirror formed is virtual, so it is entered as a negative number in the formula. Use the object position (s) as 10, the image position (s') as -2, and derive the value of the focal length:

[tex]\frac{1}{s} +\frac{1}{s'}=\frac{1}{f}\\\frac{1}{10} +\frac{1}{-2}=\frac{1}{f}\\\frac{1}{10} -\frac{1}{2}=\frac{1}{f}\\\frac{10\,f}{10} -\frac{10\,f}{2}=\frac{10\,f}{f}\\f-5\,f=10\\-4\,f=10\\f=-2.5\,\,cm[/tex]

Answer:

In the data table, we can see the frequency distribution in the diet of a given type of chimpanzee.

Why a researcher further classify the data separating information of males and females?

Well, the objective of the researcher is to find information about these chimpanzees, so if he notices that the diet varies (even slightly) between males and females, separating the information between males and females would be useful to know how the diet varies, and why this happens.

This is the primary motive of why a researcher would want to separate the information of males and females.

Answer:

the car uses teleportation, to zip to one side of the photo, to the other

Explanation:

Answer:

Average acceleration = Displacement / (time)^2

Explanation:

The unit for acceleration is

[tex]m {s}^{ - 2} [/tex]

Displacement = m

Time = s

Hence the units of displacement and time should be manipulated to get the unit of acceleration.

You can't. You can only find average velocity.

But if you also know that initial velocity is zero ... the object started from rest ... then

Avg acceleration =

2 x displacement / time-squared

Explanation:

Earth’s orbit around the Sun represented as :

1 AU = 4 inches

Therefore,

Inner edge of the Oort Cloud represented as :

10,000 AU = 40,000 / 63360 = 0.631 miles

Outer edge of the Oort Cloud represented as:

100,000 AU = 400,000 / 63360 = 6.31 miles

Answer:

The position of the particle is 6m

The velocity of the particle is 16 m/s in negative direction

The acceleration of the object is -40 m/s²

Explanation:

Given;

motion of the particle along a straight line as x = 6 + 4t² - t⁴

The position of the object when t = 2s

x = 6 + 4(2)² - (2)⁴

x = 6 + 16 - 16

x = 6m

The velocity of the object when t = 2s

Velocity = dx/dt

dx/dt = 8t - 4t³

when t = 2s

Velocity = 8(2) - 4(2)³

Velocity = 16 - 32

Velocity = -16m/s

Velocity = 16 m/s (in negative direction)

The acceleration of the object when t = 2s

Acceleration = d²x/dt² = 8 - 12t²

Acceleration = 8 - 12 (2)²

Acceleration =  -40 m/s²

Answer:

(B) Parachutes

Explanation:

Air resistance works to slow down trains and airplanes, so it isn't desirable.  Air resistance also causes pendulums to slow and stop.

Parachutes need air resistance to slow a person's fall.  So air resistance is desirable here.

Answer:

B i answered it it it

Explanation:

Answer:

Vibrations from neighboring atoms

Explanation:

When a rod is heated, the thermal energy transferred to the molecules of the rod causes them to vibrate faster. As the molecules near the heat source vibrate faster, they eventually transfer their excess energy to neighbouring molecules which also begin to vibrate faster. This continues until heat is distributed throughout the length of the rod.

The process described above is known as heat transfer by conduction.

Answer:

17) a) 30 kg·m/s

b) 30 kg·m/s

c) 0.3 m/s.

18) 2.4 m/s

19) 360,000 N

The different make of  car is safer because the force acting on it  is 28,800 N, resulting much less impact

Explanation:

17) By conservation of linear momentum principle, we have;

m₁·v₁ + m₂·v₂ = m₁·v₁' + m₂·v₂'

Where;

m₁ = The mass of the astronaut = 100 kg

v₁ = The initial velocity of the astronaut = 0 m/s

m₂ = The mass of the equipment box = 2.5 kg

v₂ = The initial velocity of the equipment box = 0 m/s

v₁' = The final velocity of the astronaut

v₂' = The final velocity of the equipment box = 12 m/s

The final momentum of the equipment box = Mass of the equipment box × Final velocity

a) The final momentum of the equipment box = 2.5 kg × 12 m/s = 30 kg·m/s

b) Given that the box and the astronaut will move in opposite directions, we have;

m₁·0 + m₂·0 = -m₁·v₁' + m₂·v₂'

m₁·v₁' = m₂·v₂'

Therefore, the momentum of the astronaut will be equal to the momentum of the equipment box = 30 kg·m/s

c)  The velocity of the astronaut is given by th following relation;

100×0 + 2.5×0 = -100×v₁' + 2.5×12

100×v₁' = 2.5×12

v₁' = 2.5×12/100 = 30/100 = 0.3 m/s

The final velocity of the astronaut = 0.3 m/s.

18) By conservation of linear momentum principle, we have;

m₁·v₁ + m₂·v₂ = m₁·v₁' + m₂·v₂'

Where;

m₁ = The mass of the railway truck= 4000 kg

v₁ = The initial velocity of the railway truck= 8 m/s

m₂ = The mass of the stationary truck = 6000 kg

v₂ = The initial velocity of the stationary truck = 0 m/s

v₁' = The velocity of the two trucks immediately after collision

Therefore, we have;

4000 kg × 6 m/s + 6000 × 0 = (6000 + 4000) × v₁' = 10,000·v₁'

24,000 kg·m/s = 10,000·v₁'

v₁' = 24,000/10,000 = 2.4 m/s

The velocity of the two trucks immediately after collision is = 2.4 m/s

19) The change in kinetic energy of the car due to the collision = 1/2·m·(v₂² - v₁²)

The initial velocity of the car, v₁ = 12 m/s

The final velocity, v₂ = 0 m/s

The mass of the car, m= 600 kg

The time in which the car is brought to rest = 2 seconds

Initial time at point of collision, t₁ = 0 s

Time after collision, t₂ = 0.02 s

By Newton's second law of motion, we have

The force F acting on the car = Rate of change in momentum produced by the force

F = m × dv/dt

Force  = m × (v₂ - v₁)/(t₂ - t₁) = 600×(0-12)/(0.02 - 0) = -360,000 kg·m/s²

The force acting on the car  is equal and opposite to the force of the car =  360,000 N

b) For the different make of the car, we have;

m × (v₂ - v₁)/(t₂ - t₁) = 600×(0-12)/(0.25 - 0) = -28,800 kg·m/s². = -28,800 N

Therefore, the different make of  car is safer because the force acting on it  is 28,800 N, resulting much less impact.

Answer:

C. Meter

Explanation:

The International System of Unit (SI) is gotten from the french word Systeme international is a modern form of metric measurement. It is the system of measurement that is universally accepted. It is from this SI units that all other system of units are derived. There are seven basic SI units which are:

1) Length in Meter (m)

2) Time in Seconds (s)

3) Amount of Substance in mole (m)

4) Electric current in ampere (A)

5) Temperature in kelvin (k)

6) Luminous intensity in candela (cd)

7) Mass in kilogram (kg)

Answer:

Space in the astronomy and cosmology space is 3 dimensional region and earth atmosphere end is called space.

Explanation:

Space is the everything of the top earth atmosphere moon, starts, milky way, black hole and GPS satellites an distant,space also called between stars,moon,planet.

Space is all the extends far in all directions, space is finite unbound space surface of the earth has finite are no beginning or not end.

Space contains there are three dimensions is called 3 D space,an space is to refer an interval during signal transmitted also used by the character, bytes, words and octets in  digital signal.

space is that term can refer to various in science, communications and mathematics,and maintain orbits for responsible time, space is usually to begin at the lowest attitude satellites  can maintain orbits.

space coordinates are uniquely define the location of any particular point  and that continuum requires more than coordinates,and the number of dimensions and conventional space or digital communications during the  signal represents logic is 0 words in a digital signal.  

Explanation:

Given that,

Mass of a man, m = 75 kg

(1) We need to find the reading of the weighing machine when the lift is moving upwards with an acceleration of 2 m/s². When the lift is moving upward, reading of the weighing machine is given by :

R = m(g+a)

R = 75 (9.8+2)

R = 885 N

(2) When the lift is moving downwards with a constant velocity of 1.5m/s. It means that the lift is at rest. So, the reading is :

R = mg

R = 75 (9.8)

R = 735 N

(3) When the lift is moving downwards with an acceleration of 2.5 m/s². In this case,

R = m(g-a)

R = 75 (9.8-2.5)

R = 547.5 N

Hence, this is the required solution.

Explanation:

[tex]centripetal \: force = \frac{m {v}^{2} }{r} [/tex]

Centripetal force = 45 * 2 = 90 N

Therefore, centripetal force acting on a 45 kg boy riding in one of the cars when the car is on the top of the ferris wheel is 90 N.

The force exerted by the seat on the boy when the car is at the top of the ferris wheel is a centrifugal (pseudo force) acting (since the since the seat is in non- inertial frame) in exact opposite direction (Outwards) as the centripetal force and is equal in magnitude.

Answer:

Option D (Electricity can flow through it under special conditions ) seems to be the correct choice.

Explanation:

Other options that are provided are not related to the given theory. So that the above would be the correct choice.

Statement "Lack free electrons that can move to other atoms " describe semi-conductor.

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Answer:

D. 288 psig

Explanation:

The storage cylinder of recovered R-404A is a mixture of R-125, R-143 and R-134. The refrigeration sector has low temperatures for installation. The pressure of cylinder at 80 F will be 288 psig. The pure refrigerants have inside a container have saturation temperature which is equal to ambient temperature.

Answer:

The frequency at which the string will create a standing wave be  with three loops is 8.6 Hz

Explanation:

The speed of the of the wave, v = 12.9 m/s

The number of loops of the standing wave = 3 loops

The length of the string = 2.00 m

Given that one loo = half of the wavelength, we have;

Three loops = 3 × half = One and half wavelength  = 1.5·λ

The frequency of a wave = f = v/λ

Therefore, we have;

The frequency, f = 12.9/1.5 = 8.6 Hz

The frequency at which the string will create a standing wave be  with three loops = 8.6 Hz.

Answer:

9.675

Explanation:

got it right on acellus

Answer:

Positive

Explanation:

In an endothermic reaction, the products are at a higher energy than the reactants. This means that the enthalpy change of the reaction (∆H) is positive

Answer:CcCcccccc

Explanation:

Rfsgqh

Answer; 4.4cm

Explanation: There is a ruler upon which the cylinder start from 1.4cm and reaches 10.2cm

distance traveled =10.2-1.4=8.8

since this cylinder is small so the linear distance can be approximately taked as rotational distance(as in case of point charge) so

2x2πxr =8.8

so the circumference will be 2πr=4.4cm

Answer:

T= 2.66 seconds

Explanation:

Convert 80 km to m, which would be 0.08 m

[tex]t = d \div s[/tex]

[tex]t = 0.08 km\div 108kmph[/tex]

[tex]t = 0.00074074074 \: h[/tex]

[tex]1 \: hour = 3600 \: sec[/tex]

[tex] \frac{1}{3600} \times \frac{0.00074}{x} [/tex]

[tex]0.00074074074h \times 3600s = 2.66s[/tex]

Answer:

Both are the same.

Explanation:

[tex]pressure= \frac{force}{area} = \frac{f}{a} = \frac{n}{m {}^{2} } [/tex]

The SI unit was named after Bláise Pascal to honor him.

Hope this helps ;) ❤❤❤

Answer:

The retina comprises of rod and cone cells . The rod cells are responsible for black and white vision and require low light levels while the cone cells are responsible for color vision and require good/high light levels for better functioning.

When faint stars are looked at on the edges of the vision it allows more light from faint objects to strike the rod cells which then becomes more visible.

Answer:

9 and 4

Explanation:

The relation is:

● r = s^2 / t^2

Triplind s means multiplying it by 3. Since it's an equation we should multiply both sides by the same number

Let k be the number we should multiply by r

●k* r = (3s)^2 / t^2

●k* r = 9s^2 /t^2

We have multiplied s^2 by 9 so we should do the same for r.

k = 9

■■■■■■■■■■■■■■■■■■■■■■■■■■

Doubling t means multiplying it by 2.

Let x be the number we shoukd multiply by r.

● x* r = s^2/(2t)^2

● x*r = s^2/ 4t^2

We have multiplied t^2 by 4 so we should do the same for r.

x= 4