Question

A mass of 20kg which moved vertically produced a momentum of 300kg.m/s, how much power was needed to move the mass?

Answer 1

Answer:

Power is 3000 W

Explanation:

Momentum = mass × velocity

$300 = 20 \times v \\ velocity = 15 \: {ms}^{ - 1}$

For power:

$P = \frac{force \times distance}{time} \\ \\ P = force \times ( \frac{distance}{time} )$

but distance/time is velocity, so:

$P = force \times velocity$

but force = mass × acceleration:

$P = (mass \times acceleration) \times velocity \\ P = (20 \times 10) \times 15 \\ P = 3000 \: \: watts$

[ taken acceleration to be 10 m/s² ]