Finding Magnitude of Acceleration using the force

[ilovemynny]

Homework Statement

Car 1: 2000 kg
Car 2: 3000 kg
coefficient of friction: 1.5
angle of movement: 40 degrees North of East
displacement of vehicles: 6.0 m

What was the friction force that acted upon the locked sliding cars to stop them?

What was the magnitude of the acceleration that this force produced on the sliding cards sliding together?

Homework Equations

Ff = coe of fric x mass x 9.81

The Attempt at a Solution

so to figure out the friction force I did:
(1.5)(2000 + 3000)(9.81) = 73575 N

but I don't know how to figure out the magnitude of acceleration!
would the formula be this? coe of fric x 9.81 ?

If that isn't the formula can someone please help me?

 

[vela]

Use Newton's second law.