Question

A baseball is traveling (+30m/s) and is hit by a bat. It leaves the bat traveling (−40m/s). What is the change in its velocity?

Unlike some others, this is any choice, so not just 4 choices!

Answer 1

Step-by-step explanation:

The change must be 30 - - 40 which means it came in a 30 meters / second and went out in the opposite direction at 40 meters / second

The change is 70 m/sec.

You could show it to be - 70 meters per second as well. That's done by making the outgoing direction minus.

Delta v = vf - vi.

Now it depends on which way you define vf and vi.