Question

If a 950 kg car has 30,400 J of kinetic energy, how fast is it moving?

Answer 1

Hello

The kinetic energy K of a moving object is:
$K= \frac{1}{2} m v^2$
where m is the mass and v the velocity of the object.
Using this formula, we can calculate v for this problem:
$v= \sqrt{ \frac{2E}{m} }= \sqrt{ \frac{2\cdot30400~J}{950~Kg} } = 8~m/s$