Question

9. A baseball is traveling (+20 m/s) and is hit by a bat. It leaves the bat traveling (-30 m/s). What is the change in the velocity? Remember that direction is what makes velocity different than speed.

Answer 1

Answer:

-50 m/s

Explanation:

In order to correctly calculate the change in velocity, we have to define a positive direction. Let's take the initial direction of the ball as positive direction.

This means that the initial velocity of the ball is:

$u=+20 m/s$

while the final velocity of the ball will be negative:

$v=-30 m/s$

Therefore, the change in velocity will be:

$\Delta v= v-u=-30 m/s-(+20 m/s)=-50 m/s$