Question

Derive the relation between kinetic energy and momentum. [3 MARKS]

Answer 1

Each point: 1 Mark

Let the mass of the object is m and the speed of the object is v.

1. Kinetic energy (KE) = $\frac{1}{2}m{v}^2$ ................... (i)

2. Momentum (P) = mv ...................(ii)

Dividing and multiplying equation (i) by m, we get,

KE = $\frac{{\left(mv\right)}^2}{2m}$ .....................(iii)

now, substituting the value of P from eq (ii) in eq (iii), we get,

3. KE = $\frac{P^2}{2m}$