Question

Two cars collide at an intersection. Car A, with a mass of 1800kg , is going from west to east, while car B , of mass 1400kg , is going from north to south at 17m/s . As a result of this collision, the two cars become enmeshed and move as one afterwards. In your role as an expert witness, you inspect the scene and determine that, after the collision, the enmeshed cars moved at an angle of 65? south of east from the point of impact.

A) How fast were the enmeshed cars moving just after the collision?

B) How fast was car A going just before the collision?

Answer 1

A) Vf = 8.21 m/s

B) Va = 6.17 m/s

Step-by-step explanation:

By conservation of the linear momentum on each axix:

x-axis:

ma*Va = (ma+mb)*Vf*cos(65°)

y-axis:

-mb*Vb = -(ma+mb)*Vf*sin(65°)

By dividing both equations:

`(ma*Va)/(-mb*Vb) =(cos(65\°))/(-sin(65\°))`

Solving for Va:

Va = 6.17 m/s

Replacing this value into the x-axis equation:

Vf = 8.21 m/s