Answer:I think it’s D
Explanation:
Conduction needs direct touch to transfer
Jeff throws a ball straight up. For which situation is the vertical velocity zero?
a. on the way up
b. at the top
c. on the way back down
d. none of the above
Answer:
b. at the top
Explanation:
At the top of the climb, the vertical velocity of Jeff's throw has a value of zero.
Vertical velocity in this instance is acting against the acceleration due to gravity.
At the top of the thrown, the force of the throw becomes zero and the velocity also becomes zero. As the body finds it way downward, it begins to fall freely. The fall is due to the acceleration due to gravity which is experienced by every object on earth.An 69-kg jogger is heading due east at a speed of 1.6 m/s. A 63-kg jogger is heading 14 ° north of east at a speed of 1.5 m/s. Find (a) the magnitude and (b) the direction of the sum of the momenta of the two joggers. Describe the direction as an angle with respect to due east.
Answer:
[tex]P=203.3819375kg.m/s\\P\approx203.4kg.m/s[/tex]
[tex]\theta=6.4541\textdegree North East\\\theta\approx6.5\textdegree North East[/tex]
Explanation:
From the question we are told that
Mass of first jogger [tex]M=69kg[/tex]
Speed[tex]v_1=1.6m/s[/tex]
Direction [tex]d= East[/tex]
Mass of 2nd jogger [tex]M=63kg[/tex]
Speed [tex]v_2=1.5m/s[/tex]
Direction [tex]d= 14\textdegree north[/tex]
Generally equation for momentum along the the horizontal is mathematically given as
[tex]P_x=m_1v_1 +m_2v_2cos\theta[/tex]
[tex]P_x=(69)*(1.6) +(63)*(1.5)cos14[/tex]
[tex]P_x=202.0929461kg.m/s[/tex]
Generally equation for momentum along the the vertical is mathematically given as
[tex]P_y=m_2v_2cos\theta[/tex]
[tex]P_x=22.86161913kgm/s[/tex]
a)Generally the magnitude of momentum is mathematically given by
[tex]P=\sqrt{(P_x)^2+(P_y)^2}[/tex]
[tex]P=\sqrt{(202.0929461)^2+(22.86161913)^2}[/tex]
[tex]P=\sqrt{41364.21249}[/tex]
[tex]P=203.3819375kg.m/s[/tex]
[tex]P\approx203.4kg.m/s[/tex]
b) Generally the angle [tex]\theta[/tex] is mathematically given by
[tex]\theta=tan^-^1\frac{py}{px} \\[/tex]
[tex]\theta=tan^-^1\frac{22.86161913}{202.0929461}[/tex]
[tex]\theta=tan^-^1(0.1131242805)[/tex]
[tex]\theta=6.4541\textdegree North East[/tex]
which property of a conducting wire is utilised in making electric fuse
Answer:
property of low melting point
Explanation:
When too much current flows through the low resistance element of the fuse, the element melts and breaks the circuit
A ball is thrown with 50J of kinetic energy, it hits a target which moves with 30J of kinetic energy, how much energy goes to the thermal store of the surroundings?
Answer:
The energy that will go will for thermal store of the surroundings is 20 J.
Explanation:
Given;
kinetic of the thrown ball, K.E₁ = 50 J
kinetic energy used to move the target, K.E₂ = 30 J
The excess energy that will go will for thermal store of the surroundings;
ΔK.E = K.E₁ - K.E₂
ΔK.E = 50J - 30J
ΔK.E = 20 J
Therefore, the energy that will go will for thermal store of the surroundings is 20 J.
Please what is the work done by a man who is pulling a box of 45kg of mass by means of rope which makes angle of 45 degrees ?
Answer:
No work is done since no distance is given
Explanation:
Since no distance is given, the force is not doing any work
No work is done by the man since we do not know the distance or displacement.
Work is only said to be done when the force applied on an object moves it through a particular distance.
Work done = Force x distance.
Since no distance is given in this problem, we can as well assume that the force applied is doing no work on the object.
How does a wheel and axle make work easier?
The wheel and axle is a simple machine that reduces the friction involved in moving an object, making the object easier to transport. ... Once the object is moving, the force of friction opposes the force exerted on the object. The wheel and axle makes this easier by reducing the friction involved in moving an object.
In addition to reducing friction, a wheel and axle can also serve as a force multiplier, according to Science Quest from Wiley. If a wheel is attached to an axle, and a force is used to turn the wheel, the rotational force, or torque, on the axle is much greater than the force applied to the rim of the wheel.
2) Ariel dropped a golf ball from her second story window. The ball starts from rest and hits the sidewalk 1.5 s later with a velocity of 14.7 m/s. Find the average acceleration of the golf ball.1.5x14.7 =22.05
Answer:
Acceleration = 9.8m/s²
Explanation:
Given the following data;
Initial velocity = 0m/s (since it's starting from rest).
Final velocity, v = 14.7m/s
Time, t = 1.5 seconds.
To find acceleration;
In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.
This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.
Hence, if we subtract the initial velocity from the final velocity and divide that by the time, we can calculate an object’s acceleration.
Mathematically, acceleration is given by the equation;
[tex]Acceleration (a) = \frac{final \; velocity - initial \; velocity}{time}[/tex]
[tex]Acceleration = \frac{v - u}{t}[/tex]
Substituting into the equation, we have;
[tex]Acceleration = \frac{14.7 - 0}{1.5}[/tex]
[tex]Acceleration = \frac{14.7}{1.5}[/tex]
Acceleration = 9.8m/s²
Therefore, the average acceleration of the golf ball is 9.8m/s².
How many Joules of energy are required to make 50 kg of ice completely melt?
Hv = 226,000 J/kg
Hf = 334,000 J/kg
Answer:
In order to answer this question, you need the enthalpy of fusion of ice, which is 333.55 J/g (Joules/gram). The enthalpy of fusion is the amount of heat that must be absorbed or lost in order to change physical state.
The number of Joules required to melt the ice = enthalpy of fusion of ice x mass of ice.
1 kg = 1000g
40kg x (1000g/1kg) = 40,000g
Joules needed to melt the ice = 333.55 J/g x 40000 g = 13342000 J or
1.3342 x 107 J
Explanation:
Instead of 40kg input 50kg and get the answer
A cell of e.m.f 1.5 v and internal resistance 2.5 ohm is connected in series with an ammeter of resistance 0.5 ohm and a resistor of resistance 7.0 ohm. Calculate the current in the circuit.
Answer:
The current in the circuit is 0.15 Ampere
Explanation:
The given parameters of the cell are;
The electromotive force (e.m.f.) of the cell, E = 1.5 V
The resistance of the cell, r = 2.5 ohm
The resistance of the ammeter = 0.5 ohm
The resistance of the resistor = 7.0 ohm
The formula for the e.m.f., E of a cell is given as follows;
e.m.f. E = I·(R + r)
Where;
I = The current in the circuit
R = The sum of the resistances in the circuit = 7.0 Ω + 0.5 Ω + 2.5 Ω = 10 Ω
Therefore, we have;
[tex]The \ current \ in \ the \ circuit, \ I = \dfrac{E}{R + r}[/tex]
Substituting the known values, gives;
[tex]I = \dfrac{1.5 \ V}{7 \ \Omega + 0.5 \ \Omega + 2.5 \ \Omega} = \dfrac{1.5 \ V}{10 \ \Omega} = 0.15 \ A[/tex]
The current in the circuit, I = 0.15 Ampere.
A vector
of magnitude 5 units and another vector ū of magnitude 3 units point in directions
differing by 60°. Find out (a) the scalar product of the two vectors and (b) the vector product of the two vectors
Answer:
7.5 units
13 units
Explanation:
[tex]|v|=5\ \text{units}[/tex]
[tex]|u|=3\ \text{units}[/tex]
[tex]\theta[/tex] = Angle between the vectors = [tex]60^{\circ}[/tex]
Scalar product is given by
[tex]u\cdot v=|u||v|\cos\theta\\ =3\cdot 5\cdot \cos60^{\circ}\\ =7.5\ \text{units}[/tex]
The scalar product of the vectors is 7.5 units.
Vector product is given by
[tex]u\times v=|u||v|\sin\theta\\ =3\times 5\sin60^{\circ}\\ =13\ \text{units}[/tex]
The vector product of the vectors is 13 units.
my friend wore a smart watch to bed,when he woke up in the morning it showed 300 steps taken how did this happen?
Answer:
Your tracker will detect your arm movement and will interpret it as steps so this is what it likely happening. Something similar happens while driving, if you go through a bumpy road or your car has a stiff suspension then this can cause the tracker to detect movement and count it as steps. Usually while driving and if you notice some vibration on your car or steering wheel you can try having your tracker a little bit more tight around your wrist and this will help decrease the amount of steps detected.
Explanation:
(Via AlvaroFitbit)
If the mass of an object increases, then its kinetic energy will ____________ because __________________________
Answer:
when mass will increase then kinetic energy will also increase because both have positive relationship
Explanation:
when volume increase then molecule come closer then more movement will occurs and kinetic energy increase
The phases of the moon are caused by which of the following
A. Earths rotation around its axis
B. Earths orbit around the sun
C. The moons orbit around the earth
D. Earths shadow falling on the moon
Answer: C: The moons orbit around the earth.
Explanation:
Can anyone help me with these questions? TIA!
(Don’t actually answer please! :) )
[tex]\huge\text{Graphs:}[/tex]
The graph of
• The I-V for Ohmic Metal wire conductor at constant temperature always shows a straight line between the Current(I) plotted at Y axis and Voltage(V) plotted at X axis. Picture 1
• The I-V graph for Diode shows that first the current is zero but as we increase the potential difference(voltage), it results in the increase in the current. Picture 2
_____________________________________ Question 8:[tex]\Large\textbf{Diode:}[/tex]
A diode is a device that allows current to flow in only one direction.
[tex]\Large\textbf{Forward and Reverse Biasing:}[/tex]
Forward Bias, When a diode is forward bias (a voltage in the "forward" direction) then the P-side of the diode is attached to the positive terminal and N-side is fixed to the negative side of the battery which is connected, current flows freely through the device. The forward bias decreases the thickness of potential barrier(The potential barrier barrier in which the charge requires additional force for crossing the region)
Reverse Bias, When a diode is Reverse bias(a voltage in the "backward direction) then the P-side of the diode is connected to the negative terminal and N-side is connected to the positive terminal of the battery which is connected. The reverse bias increases the thickness of the potential barrier resulting in the flow of no current.
[tex]\Large\textbf{Answer to the Question "Resistance"}[/tex]
The Forward bias decreases the resistance of the diode whereas the reversed bias increases the resistance of the diode. As in forward biasing the current is easily flowing through the circuit whereas reverse bias does not allow the current to flow through it.
_____________________________________ Best Regards, 'Borz'A 5.75 g bullet is fired with a velocity of 1.50 x 102 m/s toward a stationary solid block resting on a frictionless surface. The bullet embeds but the block does not move. 1. What is the change in momentum of the bullet if it embeds in the block? 2. What is the change in momentum of the bullet if it bounces off the block in the opposite direction with a speed of 100 m/s?
Answer:
1. -0.863 kgm/s 2. -1.438 kgm/s
Explanation:
1. What is the change in momentum of the bullet if it embeds in the block?
Since the block does not move, the velocity of the bullet after hitting the block , v is zero. That is v = 0 m/s
Now, the momentum change of the bullet ΔP = m(v - u) where m = mass of block = 5.75 g = 5.75 × 10⁻³ kg, u = initial velocity of bullet = 1.50 × 10² m/s and v = final velocity of bullet after hitting the block = 0 m/s (since it embeds in the block and the block does not move).
So, ΔP = m(v - u)
= 5.75 × 10⁻³ kg(0 m/s - 1.50 × 10² m/s)
= 5.75 × 10⁻³ kg(- 1.50 × 10² m/s)
= -8.625 × 10⁻¹ kgm/s
= -0.8625 kgm/s
≅ -0.863 kgm/s
2. What is the change in momentum of the bullet if it bounces off the block in the opposite direction with a speed of 100 m/s?
If it bounces off the block in the opposite direction with a speed of 100 m/s, then its final velocity is v = -100 m/s.
So, our momentum change ΔP' = m(v - u) where m = mass of block = 5.75 g = 5.75 × 10⁻³ kg, u = initial velocity of bullet = 1.50 × 10² m/s and v = final velocity of bullet after hitting the block = -100 m/s = -1 × 10² m/s
So, ΔP = m(v - u)
= 5.75 × 10⁻³ kg(-1 × 10² m/s - 1.50 × 10² m/s)
= 5.75 × 10⁻³ kg(-2.50 × 10² m/s)
= -14.375 × 10⁻¹ kgm/s
= -1.4375 kgm/s
≅ -1.438 kgm/s
The eagles suck, so do the giants and the jets and jaguars are irrelevant
anyone wanna argue
Naw ur pretty accurate, heck collage is the only football worth watching most the time. Hook'um horns!
An aeroplane of mass 30000kg produced a force of 20kN to get it to accelerate to 50m/s so it could take off. Calculate the amount of time it was accelerating for
Will mark branliest! Need working out aswell!
Answer:
[tex]75\:\mathrm{seconds}[/tex]
Explanation:
The impulse-momentum theorem states that the impulse of an object is equal to the change in momentum of that object:
[tex]\Delta p=m\Delta v[/tex].
Impulse is also given by [tex]F\Delta t[/tex] where [tex]F[/tex] is the average net force and [tex]\Delta t[/tex] is change in time.
Therefore, we can set both equations equal to each other and solve:
[tex]\Delta p= F\Delta t[/tex].
Assuming that the airplane was initially at rest, its change in momentum is:
[tex]\Delta p =m\Delta v,\\\Delta p=30,000\cdot 50=1,500,000[/tex]
Impulse is represented using [tex]Ns[/tex]. Therefore, convert [tex]20\:\mathrm{kN}[/tex] to Newtons:
[tex]20\:\mathrm{kN}=20,000\:\mathrm{N}[/tex]
Thus:
[tex]1,500,000=20,000\cdot t,\\t=\frac{1,500,000}{20,000}=\fbox{$75\mathrm{s}$}[/tex].
a cellphone weighing 80 g is flying to the air at 15 m/s what is it's kinetic energy
Answer:
9J
Explanation:
Given parameters:
Mass of cell phone = 80g
1000g = 1kg
80g is therefore 0.08kg
Velocity of the cellphone = 15m/s
Unknown:
Kinetic energy of the cellphone = ?
Solution:
The kinetic energy of a body is the energy due to its motion.
It is expressed as:
K.E = [tex]\frac{1}{2}[/tex] mv² = [tex]\frac{1}{2}[/tex] x 0.08 x 15² = 9J
MY BRAINS NOT WORKING
Describe how Newton's Third Law applies to the forces between the bike and
the trailer.
Answer:
Explanation:
The Earth pulls the bicycle downward through the force of gravity, and, in response, the bicycle pulls up on the Earth with a force of equal magnitude. Gravity "pushes" the Earth into the road, which pushes up with an opposite force, canceling gravity. Thus, action reaction forces do not cancel each other.
Select the correct answer.
A stone is dropped from a tower 100 meters above the ground. The stone falls past ground level and into a well. It hits the water at the bottom
of the well 5.00 seconds after being dropped from the tower. Calculate the depth of the well. Glven: g=-9.81 meters/second?
A.22.5 meters
B.50.7 meters
C.100 meters
D.110 meters
E.152.45 meters
Answer:
A
Explanation:
Givens
d = 100 meters plus the depth of the well
d = 100 + x where x is the depth of the well.
vi = 0 m/s The object is dropped. It was not thrown.
t = 5 seconds
a = 9.81 m/s^2
formula
d = vi*t + 1/2 a t^2
solution
100 + x = 0 + 1/2 * 9.81 * 5^2
100 + x = 122.625 Subtract 100 from both sides
x = 122.625 - 100
x = 22.6 m
The well is 22.6 meters deep.
HELP PLEASE!
A 700 kg race car makes one lap around a track. It has a velocity of 20 m/s with a centripetal force of 5,600 N. What is the radius of the track?
A speed skater goes around a turn with a 25 m radius. The skater has a velocity of 15 m/s and experiences a centripetal force of 720 N. What is the mass of the skater?
A 900-kg car moving at 5 m/s takes a turn around a circle with a radius of 30 m. Determine the net force acting upon the car.
An 800 kg race car makes one lap around a track. It has a velocity of 40 m/s with a centripetal force of 16,000 N. What is the radius of the track?
PLEASE EXPLAIN AND SHOW WORK!
The centripetal force is the force that keeps a body moving in a circular path.
The centripetal force is given by; F = mv^2/r
1) We have;
F = 5,600 N
v = 20 m/s
r =?
m = 700 kg
Making r the subject of the formula;
r =mv^2/F
r = 700 × (20)^2/5,600
r = 50 m
2) F = mv^2/r
F = 900 × (5)^2/30
F = 750 N
3) Making r the subject of the formula;
r =mv^2/F
r = 800 × (40)^2/ 16,000
r = 80 m
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1. How much heat must be absorbed by 375 grams of water to raise its
temperature by 25° C?(Cp of water is 4.184)
Answer:
39225J
Explanation:
Given parameters:
Mass of water = 375grams of water
Change in temperature = 25°C
Specific heat capacity of water = 4.184J/g°C
Unknown:
Amount of heat absorbed = ?
Solution:
To solve this problem, we use the expression below:
H = m c Ф
H is the heat absorbed
m is the mass
c is the specific heat capacity
Ф is the change in temperature
Insert the parameters and solve;
H = 375 x 4.184 x (25) = 39225J
Which of the following is BOTH an isotope and ion of Chlorine? plz help
a
B
c
D
Answer:
The answer is C.
Explanation:
because if you look ay the nutrons you can see that it adds to the protons
Answer:
C
Explanation:
Isotopes of Chlorine (Cl) gain an electron when they form ionic bonds. This results in a negative ion (the Chloride ion). ... When the charge on an atom is zero it means the number of protons is equal to the number of electrons. The atom is said to be neutral and there will not be a + or - written after the element symbol.
A solar panel gives our 250 Watts
of power in 2 seconds. How much
work did the solar panel do?
Why does Farm Bureau and other advocacy organization oppose any mandated labeling of biotech crops?
Answer:
I’m. Nog sure
Explanation:
The Periodic Table Question 4 of 10 If an element forms a 2+ ion, in which group of the periodic table would you expect to find it? D A. 2 B. 17 O C. 1 D. 18 7
Answer:
B is the difference قصدي لا انا اعرف بشير بس ما اعرف اخوه يعني *قصدي لا انا اعرف بشير بس ما اعرف اخوه يعني *قصدي لا انا اعرف بشير بس ما اعرف اخوه يعني *قصدي لا انا اعرف بشير بس ما اعرف اخوه يعني *قصدي لا انا اعرف بشير بس ما اعرف اخوه يعني *
Kinetic energy can be calculated using the formula KE = 1/2mv2. What is the kinetic energy of a bicycle that has a mass of 20 kg and is traveling at a velocity of 10 m/sec?
KE = 1000 J
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightPhysics
Energy
Kinetic Energy Formula: [tex]\displaystyle KE = \frac{1}{2}mv^2[/tex]
Energy is in Joulesm is mass (in kg)v is velocity (in m/s)Explanation:Step 1: Define
m = 20 kg
v = 10 m/s
Step 2: Find KE
Substitute [KE]: [tex]\displaystyle KE = \frac{1}{2}(20)(10)^2[/tex]Exponents: [tex]\displaystyle KE = \frac{1}{2}(20)(100)[/tex]Multiply: [tex]\displaystyle KE = (10)(100)[/tex]Multiply: [tex]\displaystyle KE = 1000[/tex]A 50Kg girl jumps off a 5-meter-high diving board. What is her kinetic energy right before she
hits the water?
A. 0 J
B. 25 J
C. 1225 J
D. 2450 J
Answer:
D is the correct answer
Explanation:
Ek=m*g*h=50*9.8*5=2450
The kinetic energy right before she hits the water is 2450J. So, the correct option is D.
What is Kinetic energy?Kinetic energy is defined as the energy that is due to the motion of an object. If we want to accelerate an object, we must apply a force, by applying a force we need to do work. After the work is done, energy has been transferred to the object, and the object will continue to move with a new constant speed.
A 50Kg girl jumps off a 5-meter-high diving board.
We need to find the kinetic energy of the girl before she enters the water which means that the kinetic energy becomes equal to the potential energy such that,
P.E.=K.E. = mgh
where, m=mass of the object
g= acceleration due to gravity [tex](9.8m/s^2)[/tex]
h= height
So, K.E= 50* 9.8*5 = 2450 J
Thus, the kinetic energy right before she hits the water is 2450J. So, the correct option is D.
Learn more about Kinetic energy, here:
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Which change of state takes place when a gas loses energy?
A. condensation
B. evaporation
C. molting
D. solidification
Answer:
Condensation (((((((((((((
A piece of glass weights 25 g in air, 16.77g in water at 4C and 16.89g in water at 60C. Find the mean coefficient of cubical expansion of water between 4C anf 60C, taking the coefficient of linear expansion of glass as 8*10^6
sorry i think so i dont exactly know i am sorry
Explanation:
As a certain amount of water is cooled from room temperature until it reaches 4 °C, its volume drops. The density reduces as the volume increases below 4 °C. Therefore, water's greatest density occurs at 4 degrees Celsius.
What coefficient of cubical expansion of water?Water has an unusual trait called anomalous expansion, which causes it to enlarge rather than compress when the temperature drops from 4 °C to 0 °C, and it becomes less dense.
At temperatures not far below zero degrees Celsius, water ice is unique for having low coefficients of static and dynamic friction that range from 0.04-0.02, but as the temperature drops, these numbers rise.
Therefore, When a metal sheet's temperature rises by one degree, its coefficient of area expansion is calculated as the increase in surface area per unit of original surface area.
Learn more about coefficient here:
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