A ball is thrown forward at relative to the ground

PHYSICS · Single correct · ISC · Physics · Kinematics · Kinematics

Problem

0.50\,\text{kg}

ball is thrown forward at

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

relative to the ground. A friend on a skateboard moves in the same direction at

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

relative to the ground. What kinetic energy does the friend assign to the ball? (a)

2\;\text{J}

(b)

1\;\text{J}

(c)

9\;\text{J}

(d)

0.50\;\text{J}