Question

During construction, a crane lifts a 2,000-newton weight to the top of a 50-meter-tall building. How much power must the crane have to perform this task in 5 seconds? Use commas where appropriate and round to the nearest tenth.

watts:

kilowatts:

horsepower:

Answer 1

Work is defined as force thru a distance: W = F * S

Power is defined as Work per unit time P = W / t

So we an write: P = F * S / t = 2000 N * 50 m / 5 s = 20,000 N-m/s

Since a Joule/sec is equivalent to a Watt

The power required is 20,000 Watts or 20 Kw

Also, you can convert to Hp since 1 Hp = 746 Watts