Question

An engine develops 20 kW power. How much time will it take to lift a mass of 200 kg to a height of 50 m? (g = 10 m/s²)

Options

• 1 sec

• 2 sec

• 5 sec

• 7 sec

Answer 1

5 sec

Explanation:

P = `"w"/"t" = "mgh"/"t"`

⇒ t = `"mgh"/"P"`

= `(200 xx 10 xx 50)/(20 xx 1000)`

= 5 sec