Answer: An 8 kg book at a height of 3 m has the most gravitational potential energy.
Explanation:
Gravitational potential energy is the product of mass of object, height of object and gravitational field.
So, formula to calculate gravitational potential energy is as follows.
U = mgh
where,
m = mass of object
g = gravitational field = 
h = height of object
(A) m = 5 kg and h = 2m
Therefore, its gravitational potential energy is calculated as follows.

(B) m = 8 kg and h = 2 m
Therefore, its gravitational potential energy is calculated as follows.

(C) m = 8 kg and h = 3 m
Therefore, its gravitational potential energy is calculated as follows.

(D) m = 5 kg and h = 3 m
Therefore, its gravitational potential energy is calculated as follows.

Thus, we can conclude that an 8 kg book at a height of 3 m has the most gravitational potential energy.
According to the Law of Conservation of Energy, energy is neither created nor destroyed. It is only transferred through different forms of energy. For the following situations, the conversion of energy is as follows:
*Turning on a space heater = electrical energy⇒heat energy
*Dropping an apple core into the garbage = potential energy⇒kinetic energy
*Climbing up a rope ladder = kinetic energy⇒potential energy
*Starting a car = chemical energy⇒mechanical energy
<span>*Turning on a flashlight = chemical energy</span>⇒electrical energy
Explanation:
because the acceleration is negative, this indicates a deceleration (or slowing down) . Hence we can say that:
The car is decelerating (slowing down), i.e its velocity is decreasing, at a constant rate of 5m/s².
Answer:
reference against doubt
Explanation:
exact standards of measurement are a reference point for situations in doubt , a line against which to test and observe.
Answer: A Motor converts electrical energy into kinetic energy, the opposite of a generator, which converts kinetic energy to electrical energy.