As this mechanical energy is associated with height, it would be "Potential Energy" in particular.
U = mgh
U = F.h
U = 1.5 * 4
U = 6 Joules
So, 6 J of energy is lost before it hits the ground.
Hope this helps!
B) Moving with zero acceleration.
Explanation:
Acceleration is defined as the rate of change of the velocity per unit time:

In a velocity-time graph, this ratio corresponds to the slope of the curve. In fact:
(change in velocity) corresponds to the increase in the y-axis
(change in time) corresponds to the increase in the x-axis
So, acceleration corresponds to the slope of the curve in a velocity-time graph. For cart C, the slope is zero, therefore the acceleration is also zero.
Answer:
Think of it like this potential energy is exactly what it sounds like it has potential. while kinetic energy which is what the body possesses by virtue of being in motion.
Explanation:
Heat does not rise or fall because it is an energy being transferred. It is the hot air which rises because colder air is denser than hotter air.