A baseball leaves a pitcher’s hand moving horizontally at

PHYSICS · Multi-part · CBSE · Physics · Work, Energy and Power · Work, Energy and Power

Problem

A baseball leaves a pitcher’s hand moving horizontally at 20 m s−120\,{\rm m\,s^{-1}}. Immediately after release, precise instrumentation indicates that the ball’s translational kinetic energy is 75 J75\,{\rm J}. Ignore any change in mass due to the ball’s spin or deformation. (a) Determine the mass of the baseball. Show all algebraic steps and include appropriate units in your answer. (b) Later in the same game, the pitcher throws the *same* baseball at 30 m s−130\,{\rm m\,s^{-1}}. Calculate the ball’s translational kinetic energy at this higher speed and comment on how it compares to the energy found in part (a).

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