Question

A baby bird falls from its nest in a tree. Luckily, Sasquatch catches the baby bird before it hits the ground, bringing it to rest. Which describes the work W done by Sasquatch on the baby bird and its change in gravitational potential energy ∆Ugrav between the nest and where it was caught?

(A) W > 0, ∆Ugrav < 0
(B) W > 0, ∆Ugrav > 0
(C) W = 0, ∆Ugrav > 0
(D) W < 0, ∆Ugrav < 0

Answer 1

(A) W > 0, ∆Ugrav < 0

Step-by-step explanation:

As we know that from work power energy theorem

Work done by all force = Change in the kinetic energy

Work done by all force(W) = - Change in potential energy(ΔU).

When the baby bird at the height from the ground that it have a positive value of potential energy and when the bird baby catch by Sasquatch the it potential energy become lesser as compare to initial position.

So the change in potential energy will become negative ans the work will become positive.

ΔU < 0

W= - ΔU

W> 0

(A) W > 0, ∆Ugrav < 0