Question

find the KEof a ball of mass 250gram moving at the speed of 90km/h

Answer 1

Mass of ball, m = 250gm = ¼kg

Speed of ball, v = 90km/h = 25m/s

Since, 1km/h = (5/18) m/s and 1gm = (1/1000) kg

So, KE of the ball = ½mv² = ½ × ¼ × 25 × 25 J = 78.125 J

Hope, this helps...