Calculating Combined Mass Motion of Two Cars

[linnus]

Homework Statement

Car A with mass 2400 kg is moving along a straight stretch of road at 45 miles per hour. Car B with mass 1100kg follows with speed 65 miles per hour. How fast is the center of mass of the 2 cars moving?

Homework Equations

Xcm=(M1X1+...+MnXn)/ (M1+...+Mn)

The Attempt at a Solution

hmm i did

(2400kg x 45mph +1100kg x 65 mph)/ (1100kg+2400kg)= 51.3 mph
But that seems a bit too easy..

 

[Dick]

May seem too easy, but that's no reason to mistrust it.

 

[linnus]

hmm so was my method right?

 

[cristo]

But that seems a bit too easy..

Homework questions aren't meant to be a trick! If you've studied, and understand the material, then often you will find the problems quite straightforward.