Given, mass of ball, m =2 kg

Kinetic energy of ball, KE = 4 J

KE = 1/2 m ${{v}^{2}}$

${{v}^{2}}$ = 2KE / m = 2 x 4 / 2 = 4

v =2 ${{ms}^{-1}}$

Kinetic energy of ball, KE = 4 J

KE = 1/2 m ${{v}^{2}}$

${{v}^{2}}$ = 2KE / m = 2 x 4 / 2 = 4

v =2 ${{ms}^{-1}}$