Conservation of Energy Test
Which of the following is the rate at which energy is transferred?
power
Which of the following parameters does not depend on how resistant a spring is to being compressed or stretched?
relaxed length
If the sign of work is negative
the displacement is in the direction opposite the force
If friction is the only force acting on an object during a given physical process, which of the following assumptions can be made in regard to the object's kinetic energy?
the kinetic energy decreases
A more powerful motor can do
the same work in a shorter time interval
Which of the following is a true statement about the conservation of energy?
total energy is always conserved
What is the kinetic energy of a .135 kg baseball thrown at 40.0 m/s?
108 J
How much elastic potential energy is stored in a bungee cord with a spring constant of 10.0 N/m when the cord is stretched 2.00 m?
20.0 J
A horizontal force of 200 N is applied to move a 55 kg television set across a 10 m level surface. What is the work done by the 200 N force on the television set?
2000 J
Ball A has triple the mass and speed of Ball B. What is the ration of the kinetic energy of ball A to ball B?
27
A 3.00 kg toy falls from a height of 1.00 m. What will the kinetic energy of the toy be just before the toy hits the ground?
29.4 J
If the displacement of a horizontal mass spring system was doubled, the elastic potential energy in the system would change by a factor of
4
How much work is down on a 20 N crate that you lift 2 m?
40 J
How much power is expended if you lift a 60 N crate 10 meters in 1 second?
600 W
What is the potential energy of a 1.0 kg mass 1.0 m above the ground?
9.8 J
Which of the following energy forms is not involved in hitting a tennis ball?
chemical potential energy
The ration of useful work output to total work input is called the
efficiency
Which form of energy is involved in weighing fruit on a spring scale?
elastic potential energy
Which of the following energy forms is associated with an object due to its position?
potential energy
A child moving at constant velocity carries a 2 N ice cream cone 1 m across a level surface. What is the net work done on the ice cream cone?
0 J
A worker does 25 J of work lifting a bucket, then sets the bucket back down in the same place. What is the total net work done on the bucket?
0 J
Which of the following are not units of power?
J
In which of the following scenarios is work down?
a car decelerates while traveling on a flat stretch of road
In which of the following scenarios is no net work done?
a car travel at constant speed on a flat road
For which of the following situations is the conservation of mechanical energy most likely to be a valid assumption?
a soccer ball flies through the air
Gravitational potential energy is always measured in relation to
a zero level
As a pendulum swings back and forth
all of the above
Energy is changed from one form to another with no net loss or gain.
always true
The work energy theorem states that the work down on an object by the net __________ is equal to the change in its _________ energy.
force, kinetic
Consider molecules of hydrogen gas and molecules of heavier oxygen gas that has the same kinetic energy. The molecules with the greater speed are
hydrogen
A force does work on an object if a component of the force
is parallel to the displacement of the object
Which of the following energy forms is associated with an object in motion?
kinetic energy
The main difference between kinetic energy and potential energy is that
kinetic energy involves motion, and potential energy involves position
Which of the following refers to the sum of kinetic energy and all forms of potential energy?
mechanical energy
An object that has kinetic energy must be
moving
