Question

A ball is thrown vertically upwards from the ground. Which of the following is correct regarding the work done by air resistance?

• A. Work done is positive during the ascent and negative during the descent
• B. Work done is positive during the ascent and positive during the descent
• C. Work done is negative during the ascent and positive during the descent
• D. Work done is negative during the ascent and negative during the descent

Answer 1

The correct option is D Work done is negative during the ascent and negative during the descent

Air resistance offers retarding force opposite to the direction of instantaneous velocity. As the force acts opposite to the displacement of the body, the work done by it is negative.