Question

You serve a volleyball with a mass of 2.1kg. The ball leaves your hand with a speed of 30m/s. The ball has _____________ energy. Calculate it.

Answer 1

• Mass=m=2.1kg
• Velocity=v=30m/s

$\\ \rm\Rrightarrow K.E=\dfrac{1}{2}mv^2$

$\\ \rm\Rrightarrow K.E=\dfrac{1}{2}(2.1)(30)^2$

$\\ \rm\Rrightarrow K.E=\dfrac{1}{2}(2.1)(900)$

$\\ \rm\Rrightarrow K.E=450(2.1)$

$\\ \rm\Rrightarrow K.E=945J$