Question

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 same horizontal line. What is the work done by the force of gravity on the object?Why? ​

Answer 1

Answer :

The work done bu the gravitational force is zero

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• Here if we take a look at the image in the attachment we may observe the we see that we have a object that is thrown from the ground with an angle θ and the object reaches back to the same ground following a curved path $\sf .$

• Here the ground is the horizontal line along with which the object start it's joinery and also end it.

• The displacement of the object is only in the horizontal direction since there is no net displacement in the vertical direction along which the gravitational force act there is no work done by gravity here.

• And hence the work done in this case by gravity will be zero.

Answer 2

Answer:

$\mapsto$ The work done by gravity is zero joule .

Explanation:

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

In this case :-

• Force is applied in the vertical direction.
• 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.

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

$\therefore$ The work done by gravity on the given object is zero joule.