A car of weight 20000 N drives up a hill at a steady speed of 8 m/s, gaining a height of 120 m in 100 s

Question

A car of weight 20000 N drives up a hill at a steady speed of 8 m/s, gaining a height of 120 m in 100 s. Calculate (i) the work done by the car and (ii) the power of the engine of the car. [(i) 24 × 10⁵ J (ii) 24 × 10³ W]

Answer

Force (F) = 20000 N

Speed (v) = 8 m/s

Height (h) = 120 m

Time (t) = 100 s

(i) Work done (W) = Force (F) × displacement (h)

= 20000 × 120

= 2400000 J or 2.4 × 10⁶ J

(ii) Power (P) = Work\over Time

= 2400000\over 100

= 24000 W or 2.4 × 10⁴ W