(a) At level A Potential Energy is 2940 J.
(b) At level B Potential Energy is 1960 J.
(c) At level C Potential energy is 1470 J.
(d) At level D Potential energy is 0 J.
(e) The change in Potential energy if the object moves from A to B is 980 J.
<u>Explanation</u>:
Given that,
Mass of an object is 5 kg (m) at a height of 60 m (h) above the ground as shown in the given figure.
Potential energy of an object is calculated by using the formula m × g × h. “g” is acceleration due to gravity on earth is 9.8 .
(a) At level A:
At height (h) is 60 m above ground.
Potential energy = 5 × 9.8 × 60
Potential energy = 2940 J
(b) At level B:
At height (h) is 40 m above ground.
Potential energy = 5 × 9.8 × 40
Potential energy = 1960 J
(c) At level C:
At height (h) is 30 m above ground.
Potential energy = 5 × 9.8 × 30
Potential energy = 1470 J
(d) At level D:
At height (h) is 0 m above ground (object is on the ground).
Potential energy = 5 × 9.8 × 0
Potential energy = 0 J
(e) Change in “Potential energy” when it moves from “A” to “B”
Change in “Potential energy” in difference in initial “Potential energy” (at level A) and final “Potential energy” (at level B)
= 2940 - 1960
= 980 J
Therefore, change in “Potential energy” is 980 J.