Question

A ball (100 gm) thrown from ground with speed
20 m/s comes back to the ground with speed
10 m/s. Find the work done by air resistance.​

Answer 1

Answer:

15J

Explanation:

m=-10^-1kg

w=1/2m(vf^2-vi^2)

=1/20(300)=15J

Answer 2

Hey Dear,

◆ Answer -

Work done by air resistance = -15 J

● Explanation -

Initial kinetic energy of ball is -

KEi = 1/2 mu^2

KEi = 1/2 × 0.1 × 20^2

KEi = 20 J

Final kinetic energy of ball is -

KEf = 1/2 mv^2

KEf = 1/2 × 0.1 × 10^2

KEf = 5 J

Therefore, work done by air resistance will be -

Work = KEf - KEi

Work = 5 - 20

Work = -15 J

Therefore, work done by air resistance is -15 J.

Thanks dear...