## Physics: Principles with Applications (7th Edition)

Let the direction from the batter to the pitcher be the positive direction. Calculate the constant force from the ball’s change in momentum, equation 7-4. $$F=m\frac{\Delta v}{\Delta t}=(0.145 kg)\frac{46.0 m/s – (-31.0 m/s)}{5.00 \times 10^-3 s}=2230 N$$ The answer is rounded to 3 significant figures.