Problems 26-30 Solutions Outline
State the work-energy principle.
The net work done on an object is equal to the change in the object's kinetic energy.
The quantity mgy is
A) the kinetic energy of the object.
B) the gravitational potential energy of the object.
C) the work done on the object by the force.
D) the power supplied to the object by the force.
The quantity 1/2 kx2 is
A) the kinetic energy of the object.
B) the elastic potential energy of the object.
C) the work done on the object by the force.
D) the power supplied to the object by the force.
Is it possible for a system to have negative potential
energy?
A) Yes, as long as the total energy is positive.
B) Yes, since the choice of the zero of potential
energy is arbitrary.
C) No, because the kinetic energy of a system must
equal its potential energy.
D) No, because this would have no physical meaning.
An object is released from rest a height h above
the ground. A second object with
four times the mass of the first if released from the same height.
The potential energy of the second object compared to the first is
A) one-fourth as much.
B) one-half as much.
C) twice as much.
D) four times as much.