Question

2. An object thrown at a certain angle to the ground moves in a
curved path and falls back to the ground. The initial and the
final points of the path of the object lie on the same horizontal
line. What is the work done by the force of gravity on the object?​

Answer 1

Answer:

suppose that you are throwing an object at initial velocity u, now let's imagine that the object makes an angle ∅ with the horizontal. Now the highest distance covered by the object will be u²sin²∅/2g

show the work done by the gravitational force will be mg[u²sin²∅/2g]

=m[u²sin²∅/2]=[mu²sin²∅]/2... where m is is the mass of the object..

Answer 2

Explanation:

Work is done when force applied produce motion in the direction of the force.

In this case :-

But the displacement of the body is the horizontal direction.

Since, angle between force and displacement is 90°.

Now, the work done is 0 as the initial and final velocity are on the same path so the height will be 0.

Force is applied in the vertical direction.

We know that,

★ W = m × g × h ★

where,

Work = Work Done

m = Mass

g = Gravity

h = Height

⇒ W = m × g × h

⇒ W = m × g × 0

➠ W = 0 J