JEE Main Physics question
It is observed that the force required to tow a boat at a constant velocity is proportional to the velocity. It takes 16 HP to tow a boat at a velocity of 2 km h⁻¹. The horse power required to tow this boat at a velocity of 3 km h⁻¹ is
Answer: (C)
Solution
P = Fv, and F ∝ v, so P ∝ v². P₂/P₁ = (3/2)² = 9/4 ⟹ P₂ = 16×9/4 = 36 HP.