(3) The frictional force exerted by the floor on the box
Explanation:
Gravitational potential energy
= mgh
= (2kg)(10N/kg)(5m)
= 100J.
Answer:
B) Power is the rate at which work is done
Answer:
E. Zero Maximum
Explanation:
At the point of maximum displacement, the speed is zero while the restoring force is maximum. In fact:
- The restoring force is given by
, where k is the spring constant and x is the displacement - at the point of maximum displacement, x is maximum, so F is maximum as well
- the total energy of the system is sum of kinetic energy and elastic potential energy:

where m is the mass of the system and v is the speed. Since E (the total energy) is constant due to the law of conservation of energy, we have that when K increases, U decreases, and viceversa. As a result, when x increases, v decreases, and viceversa. At the point of maximum displacement, x is maximum, so v will have its minimum value (which is zero, since the system is changing direction of motion).
The term you need to know is equilibrium. Technically it means that heat gained = heat lost. Normally in beginning chemistry classes the evidence for this condition is a stable temperature.