You throw a 0.50 kg ball vertically up with initial speed 15.0 m/s and catch it with your hand at the same height. What is the kinetic energy of the ball when it hits your hand at the end?
A)0 J
B)3.8 J
C)4.9 J
D)56 J

Question

Quizplus · Accepted Answer

The kinetic energy of the ball when it hits your hand at the end is the same as its initial kinetic energy because it returns to the same height, and thus its velocity is the same magnitude but in the opposite direction. Kinetic energy (KE) is given by the formula KE = 1/2 mv^2, where m is the mass and v is the velocity. Plugging in the given values, KE = 1/2 * 0.50 kg * (15.0 m/s)^2 = 0.25 * 225 = 56.25 J, which rounds to 56 J for the purposes of the options provided.

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