Question

Lawrence is able to lift 100kg to a height of 1.5m in 0.75 seconds. how much power did lawrence use?

Answer 1

Answer:

Power= 1306.67 Watt

Explanation:

Power

The concept of power is related to how long it takes to some agent to do work.  The work done by a force $\vec F$ is

$W=\vec F \cdot \vec x$

Where $\vec x$ is the displacement. The operation is known as dot-product which results in a scalar equal to the magnitude of the projection of F by the distance.

The power can be computed by

$\displaystyle P=\frac{W}{t}$

In this case, the force Lawrence is applying is the necessary to lift the object and beat its weight, so

$F=mg=100\ kg\ 9.8\ m/s^2=980\ J$

The power is:

$\displaystyle P=\frac{980}{0.75}=1306.67\ Watt$