Question

An object has 100J of KE. It has a mass of 10kg. How fast is it travelling

Answer 1

$k = \frac{1}{2} mv {}^{2}$
$100 = \frac{1}{2} \times 10 \times v {}^{2}$
$100 = 5v {}^{2}$
$v {}^{2} = 20$
$v = \sqrt{20} = 2 \sqrt{5}$