A firework of mass is at rest before it explodes into two parts having masses and

PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

A firework of mass

5\,\text{kg}

is at rest before it explodes into two parts having masses

1\,\text{kg}

and

4\,\text{kg}

. If

1000\,\text{J}

of internal energy is converted into the kinetic energy of the fragments, the speed of the

1\,\text{kg}

fragment is (a)

32\,\text{m\,s}^{-1}

(b)

20\,\text{m\,s}^{-1}

(c)

40\,\text{m\,s}^{-1}

(d)

44.7\,\text{m\,s}^{-1}