A force of 200 N is applied to a 50 kg block on a frictionless surface, causing it to accelerate. What is the work done by this force in 4 s if the block starts from rest?
Q1. A force of 200 N is applied to a 50 kg block on a frictionless surface, causing it to accelerate. What is the work done by this force in 4 s if the block starts from rest?
Answer: 3200 J
Explanation: a = F/m = 200 N / 50 kg = 4 m/s²; d = ½at² = ½ × 4 m/s² × (4 s)² = 32 m; Work = F × d = 200 N × 32 m = 6400 J, but using the work-energy theorem: Work = ΔKE = ½ × 50 kg × (16 m/s)² = 3200 J (since v = u + at = 0 + 4 × 4 = 16 m/s). Option A fails due to incorrect time application.