Question

5. When a body throw up, work done by radial force on the body is
(1 Point)
zero
Positive
negative
cannot say​

Answer 1

Hey Mate.

your answer is (B) Negative.

Answer 2

Given:

When a body throw up.

To Find:

work done by radial force on the body is?

Solution:

here, it is given that , the body is thrown up.

therefore, a force ($f_{g}$) due to gravity is acting on the body in downward direction.

Since, we know that -

work done on body is given by;

$\vec{w}=\vec{f_{g} }.\vec{d}$

since, here both force due to gravity and displacement of the body are in opposite direction, i.e., angle between them is 180 degree.

therefore,

$w=f_{g}d(cos{180})\\=-f_{g}d$

since, cos(π) = -1 and here, d is the displacement of the body.

Hence, work done by radial(gravitational) force on a body when it thrown up is negative.