(1) A boy weighing 350 N runs up a flight of 30 steps, each 20cm high in 1 minute. Calculate: (a) the work done and (b) the power spent
(2) A truck weighing 1000 kgf changes its speed from 36 km/hr to 72 km/hr in 2 minutes. Calculate: (a) the work done by the engine and (b) its power (g=10m/s²)
(3) How much energy is gained by a box of mass 20 kg when a man
(a) carrying the box waits for 5 minutes for a bus
(b) runs carrying the box with a speed of 3 metre per second to catch the bus?