# Relative Motion Problem

1. Feb 1, 2010

### MFlood7356

1. A cameraman on a pickup truck is traveling westward at 19 km/h while he videotapes a cheetah that is moving westward 38 km/h faster than the truck. Suddenly, the cheetah stops, turns, and then run at 50 km/h eastward, as measured by a suddenly nervous crew member who stands alongside the cheetah's path. The change in the animal's velocity takes 2.2 s. What are the (a) magnitude of the cheetah's acceleration according to the cameraman and the (b) magnitude of the cheetah's acceleration according to the nervous crew member?

2. Vpa=Vpb + Vba, a=V2-V1/t and Apa=Apb

3. I attempted the problem even though I was confused and got it wrong but here is my attempt:
50-57/2.2 = 0.86

2. Feb 1, 2010

### tiny-tim

Hi MFlood7356!
No, the cheetah is changing from 57 km/h westward to 50 km/h eastward.

You've calculated it for 57 km/h westward to 50 km/h westward.

(also, you mustn't use both hours and seconds!)

3. Feb 1, 2010

### MFlood7356

Okay thank you I got the right answer