Q 11-05-038NEETJEE MainMedium
A car of mass $1000$ kg moves up a slope rising $1$ m for every $20$ m along the road at a steady $36$ km/h. Friction and air resistance together are $500$ N. The power delivered by the engine is ($g = 10\ \text{m/s}^2$)
Answer: (A) $10$ kW
Concept. Steady speed: engine force $= mg\sin\theta +$ resistance; $P = Fv$.
Step 1. Force. $1000 \times 10 \times \dfrac{1}{20} + 500 = 1000$ N.
Step 2. Power. $1000 \times 10 = 10$ kW.
Answer. $10$ kW (Option A).
Solution by Sreeraj P, M.Sc Physics