Question

A 2.0 kg mass has 300 J energy. What is the speed of the mass

Answer 1

The kinetic energy of the body is

$\displaystyle E = \frac{mv^2}{2} = 300 \; J$ .

The mass is given: $m=2.0 \; kg$.

So, the speed is

$\displaystyle v = \sqrt{\frac{2E}{m}} = \sqrt{\frac{600}{2}} = \sqrt{300} \approx 17.3 \; \frac{m}{s}.$

Answer: 17.3 m/s.