Question

a baseball is traveling $(+30\\ m/s)$ and is hit by a bat. it leaves the bat traveling $(-40\\ m/s)$. what is the change in the velocity? remember that direction is what makes velocity different than speed. -10 m/s -30 m/s -40 m/s -70 m/s

Explanation:

Step1: Recall the formula for change in velocity

The formula for change in velocity \(\Delta v\) is \(\Delta v=v_f - v_i\), where \(v_f\) is the final velocity and \(v_i\) is the initial velocity.

Step2: Substitute the given values

Given \(v_i = + 30\space m/s\) and \(v_f=-40\space m/s\). Then \(\Delta v=-40-(+30)\).
Using the rule \(a - b=a+(-b)\), we have \(\Delta v=-40+( - 30)\).
Adding the two negative numbers: \(\Delta v=-(40 + 30)=-70\space m/s\)

Answer:

\(-70\space m/s\)