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Worksheets3-1-24 ch 4 quiz
Total questions: 67
Worksheet time: 34mins
_______ is force applied through a distance.
Effort
Resistance
Power
Work
In which of the following situations do your arms do work on books?
holding a heavy stack of books while standing
carrying a heavy stack of books
dropping a stack of books onto a table
picking up a pile of books from the floor
Which of the following equations should be used to calculate work done?
W = F × d
W = F/d
W = F × a
W = m × d
You apply a force of 18 N to a dresser and move it 3.0 m. How much work did you do on the dresser?
54 J
6.0 J
21 J
27 J
A couch is pushed with a horizontal force of 80 N and moves a distance of 5 m across the floor. How much work is done in moving the couch?
40 J
400 J
800 J
250 J
How much work do you do when you lift a 100 N child 0.5 m
100 J
200 J
50 J
400 J
The brakes on a car do 240,000 J of work in stopping the car. If the car travels a distance of 40 m while brakes are being applied, how large is the average force that the brakes exert on the car?
9,600,000 J
9,600,000 N
6000 J
6000 N
The force needed to lift an object is equal in size to the gravitational force on the object. How much work is done in lifting an object that has a mass of 5 kg a vertical distance of 2 m.
112 J
28 J
98 J
10 J
If an object is moved 2 m and has a total work performed on it of 25 J how many newtons of force were applied?
100 N
50 N
480 N
12.5 N
If an object has 100 J of work done on it with a force of 25 N applied to it how far does the object move?
1 m
2 m
3 m
4 m
5 m
How does a ramp make it easier to move a heavy object a certain distance?
by decreasing the amount of force required to move the object
by decreasing the amount of work required to move the object
by decreasing the distance the object moves
by increasing the amount of force required to move the object
A _______ is a device that does work with only one movement
compound machine
hand-operated machine
force multiplier
simple machine
is a combination of 2 or more simple machines
compound machine
hand-operated machine
force multiplier
simple machine
is a device that changes the force or increases the motion from work.
compound machine
machine
force multiplier
simple machine
The equation for efficient is?
efficiency % = [ (W in) / (W out) ] * 100
efficiency % = [ (W in) (W out) ] 100
efficiency % = [ (W out) / (W in) ] * 100
efficiency % = [ (W out) (W in) ] 100
If we have a pulley system in which we put 700 J of work into the system and we get 400 J of work out what is the efficiency of the pulley system?
1.75 %
175%
0.57 %
57%
A machine has a efficiency of 40% if the machine does 800 J of work what is the input work?
2000 J
320 J
32,000 J
6000 J
If the input work on a pulley system is 75J and the system is 84% efficient what is the output work of the pulley system?
0.89 J
63 J
6300 J
450 J
Workers do 8,000 J of work on a 2,000 N crate to push it up a ramp. If the ramp is 2 m high, then hat is the efficiency of the ramp?
25%
50%
75%
100%
The equation for mechanical advantage is?
MA = (F out) / (F in)
MA = (F out) * (F in)
MA = (F in) / (F out)
MA = (F in) * (F out)
calculate the mechanical advantage of a hammer if the input force is 125 N and the output force is 2,000 N
16
8
0.0625
4
Find the force needed to life a 3,000 N weight using a machine with a mechanical advantage of 15.
200 N
100 N
45, 000 N
10,000 N
When work is done, there is always a(n) _______.
constant rate
single movement involved
transfer of energy
increase in the mechanical advantage
______ is the ability to cause change.
Momentum
Work
Power
Energy
What two factors determine how much kinetic energy an object has from its motion?
the object's position and mass
the object's speed and surface area
the object's speed and mass
the object's speed and position
_______ is stored energy due to the interactions between objects.
Potential energy
Entropy
Thermal energy
Kinetic energy
The _______ is the SI unit of energy.
watt
joule
ampere
volt
Which has the most kinetic energy from its motion?
a 900-kg car traveling 22.2 m/s
a 1,100-kg car traveling 16.7 m/s
a 2,000-kg truck traveling 13.9 m/s
a 300-kg motorcycle traveling 27.8 m/s
Approximately how much kinetic energy does an object have from its motion if its mass is 150-kg and it is moving at a speed of 5.0 meters per second?
400 J
1,875 J
3,800 J
57,000 J
A ball with a mass of 0.15 kg is moving at a speed of 40 m/s. What is the baseball's kinetic energy from this motion
240 J
1200 J
120 J
750 J
A 1500 kg car doubles its speed from 14 m/s to 28 m/s. By how many times does the kinetic energy from the car's forward motion increase?
kinetic energy is the same
kinetic energy doubles
kinetic energy is 4x
kinetic energy is 8x
We have 2 objects one has a mass of 500 kg the other has a mass of 1000 kg both are moving at the same velocity of 28 m/s westward. How much more kinetic energy does the object that is 1000 kg have?
kinetic energy is the same
kinetic energy doubles
kinetic energy is 4x
kinetic energy is 8x
If an object has 500 J of kinetic energy and has a mass of 10 kg how fast is the object moving?
100 m/s
10 m/s
1 m/s
25 m/s
If an object has 25,000 J of kinetic energy and has a mass of 200 kg how fast is the object moving?
5 m/s
10 m/s
16 m/s
25 m/s
If an object has a velocity of 20 m/s and has 2,500 J of kinetic energy what is its mass?
12.5 kg
156.25 kg
73.26 kg
27.46 kg
If an object has a velocity of 50 m/s and has 200,000 J of kinetic energy what is its mass?
40 kg
80 kg
160 kg
320 kg
______ is energy stored by things that stretch or compress.
Elastic kinetic energy
Gravitational potential energy
Elastic potential energy
Chemical kinetic energy
Stored energy due to chemical bonds is _______.
chemical potential energy
chemical kinetic energy
energy of activation
thermal potential energy
What two factors affect how much gravitational potential energy an object-Earth system has?
the object's mass and height above the reference point
the object's speed and mass
the object's speed and surface area
Earth's size and the object's mass
What is the approximate gravitational potential energy of a diver-Earth system, if the diver has a mass of 75-kg and is 5.0 m above the reference level?
150 J
15 J
3,675 J
370 J
What is the approximate gravitational potential energy of a object-Earth system, if the object has a mass of 125-kg and is 25.0 m above the reference level?
10,250 J
15,726 J
25,659 J
30,625 J
What is the approximate mass of a object in a object-Earth system, if the object has a GPE of 25,000 J and is 15.0 m above the reference level?
17 kg
76 kg
170 kg
326 kg
What is the approximate mass of a object in a object-Earth system, if the object has a GPE of 50,000 J and is 27.0 m above the reference level?
189 kg
176 kg
125 kg
100 kg
What is the approximate height of a object in a object-Earth system, if the object has a GPE of 50,000 J and a mass of 25 kg?
252 m
204 m
189 m
76 m
What is the approximate height of a object in a object-Earth system, if the object has a GPE of 40,000 J and a mass of 250 kg?
5 m
11 m
16 m
21 m
As energy transformations occur within a system, the total energy of the system _______.
increases
decreases
is transferred out of the system
remains constant
During energy transformations, energy is never _______.
released as heat
used to increase an object's potential energy
completely transformed
created or destroyed
The sum of the kinetic energy and the potential energy of the objects in a system is called _______.
thermal energy
complete energy
energy maximum
mechanical energy
Elastic potential energy is a form of mechanical energy
true
False
Chemical potential energy is a form of mechanical energy
true
False
gravitational potential energy is a form of mechanical energy
true
False
A light bulb expends 2000 J of energy in 20 seconds how much power did the lightbulb use?
0.01 W
1 W
10 W
100 W
An electric space heater uses 10,000 J over 10 seconds how much power did the heater use
0.001 W
1 W
100 W
1000 W
If a lightbulb is rated at 200 W and is on for 10 seconds how much energy was consumed?
0.05 J
2000 J
200 J
50 J
If a lightbulb is rated at 250 W and is on for 15 seconds how much energy was consumed?
0.06 J
3750 J
2750 J
150 J
If a light bulb is rated for 200 watts and consumes 2000 J of electricity how long was the lightbulb on
0.1 seconds
1 second
10 seconds
100 seconds
If a light bulb is rated for 100 watts and consumes 3000 J of electricity how long was the lightbulb on
0.3 seconds
3 seconds
30 seconds
300 seconds
One food calorie is equivalent to approximately _______.
4 J
40 J
400 J
4,000 J
Which is NOT a form of energy?
friction
thermal
electrical
chemical
Approximately how much work do you do when you lift your 10.0 kg sister to a height of 1.5 m?
150 J
15 J
15 N
15 W
When a machine does work on an object the output work is _______.
always less than the input work
always equal to the input work
always greater than the input work
sometimes equal to the input work
If the input force on a lever is 200 N, then the output force from that lever is 50 N. What is the mechanical advantage of the lever?
1.0
0.25
4.0
6.0
A particular lever is 90% efficient. If 50 J of work are done on the lever, then how much work does the lever do on its load?
40 J
45 J
60 J
90 J
The mechanical advantage of a pulley system is 5.0. Using this pulley system, how much force do you need to exert to lift a 500.0 N box?
100.0 N
250.0 N
500.0 N
125.0 N
Which of the following efficiencies is possible for a pulley system?
exactly 100%
exactly 400%
greater than 100%
less than 100%
Which sequence describes the energy conversions in a car's engine?
chemical to thermal to mechanical
mechanical to thermal to chemical
thermal to mechanical to chemical
kinetic to potential to mechanical
A 10-kg box sits on the floor. Approximately how high would you have to lift the box to increase gravitational potential energy by 350 J?
3.5 m
7.0 m
15 m
40 m
