Question

How much energy is gained by a box of mass $20kg$ when a man.

(ii) runs carrying the box with a speed of $3m{s}^{-1}$to catch the bus?

Answer 1

Step 1: Given data:

Mass $m=20kg$

Velocity $v=3m{s}^{-1}$

Step 2: Find the energy gained by a box:

The energy gained by a box is equal to the kinetic energy of man.

$KE=\frac{1}{2}m{v}^2$, where $KE$ is kinetic energy, $m$ is mass and $v$ is velocity.

$KE=\frac{1}{2}\times 20\times {\left(3\right)}^2$

$=\frac{1}{2}\times 20\times 9$

$=10\times 9$

$=90J$

Hence, the energy gained by a box of mass 20kg runs carrying the box with a speed of $3m{s}^{-1}$ to catch the bus is $90J.$