Question

A ball is thrown vertically upwards from the ground.Work done by air resistance during its time of flight is …...............
Positive during ascent and negative during descent.
Positive during ascent and descent.
Negative during ascent and positive during descent.
Negative during ascent andd descent. Choose the correct one and explain.

Answer 1

Answer:

Negative during ascent and descent

Explanation:

The air will resist the movement of the ball so it'll slow it down during ascent as well as descent

Answer 2

A ball is thrown vertically upwards from the ground.Work done by air resistance during its time of flight is Negative during ascent and descent.

Explanation:

• Air resistance provides a restraining force in the opposite direction of instantaneous velocity.
• Because the force acts in the opposite direction as the body's displacement, the work done by it is negative.
• The rise time is shorter than the fall time. If we throw a ball up with velocity V1 and it returns with velocity V2, the velocity is obviously V2∠V1 due to energy dissipated due to air friction.
• This signifies that the average velocity during climb is greater than the average velocity during descent. Because the displacement is the same in both circumstances, the time of rise is shorter.

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