Practice question
Question
A 0.9g drop falls from 150m and hits the ground at 13m/s. What is the work done by air resistance? (Take g\=10m/s2)
Explanation
Work W=F·d=Fd cosθ per NCERT Chapter 6. Positive if force along displacement. Using given F, d, θ, calculation gives -1.27 J. Work-energy theorem W=ΔK confirms. So option B is correct.