Question

A body of mass 5 kg moving with a velocity of 7 m m per second

Answer 1

Kinetic energy is given by = 1/2(mv^2)
K.E = 1/2(5x7^2)
= 1/2(245)
= 122.5kg mm/sec

Answer 2

Mass of the body, m = 5 kg

Velocity of the body, v = 7 m/s

1. Momentum, p = mv

• p = 5 × 7

• p = 35 kg-m/s

2. Kinetic energy, $\sf E_k$ = $\dfrac{1}{2}$mv²

• $\sf E_k$ = $\dfrac{1}{2}$× 5 × 7 × 7

• $\sf E_k$ = $\dfrac{5×49}{2}$

• $\sf E_k$ = $\dfrac{245}{2}$

• $\sf E_k$ = 122.5 J

$\bold{Hope\;it \; helps\;!}$