Question

a bat hits a 0.150 kg baseball for 0.0930 s. the balls velocity changes from -47.0 m/s to +32.0 m/s. what impulse was given to the ball? ? n·s remember to indicate the direction (+ or -)

Explanation:

Step1: Recall impulse - momentum theorem

Impulse $J = \Delta p$, where $\Delta p=m\Delta v$.

Step2: Calculate the change in velocity

$\Delta v=v_f - v_i$, with $v_f = 32.0\ m/s$ and $v_i=- 47.0\ m/s$. So $\Delta v=32.0-(-47.0)=32.0 + 47.0=79.0\ m/s$.

Step3: Calculate the impulse

$m = 0.150\ kg$, and $J=m\Delta v$. Substitute the values: $J=(0.150\ kg)\times(79.0\ m/s)=11.85\ N\cdot s$.

Answer:

$11.85\ N\cdot s$