1. The problem statement, all variables and given/known data A 1000kg car pushed a 2000kg truck. When the driver steps on the accelerator, the drive wheels of the car push against the ground with a force of 4500 N. What is the magnitude of the force of the car on the truck? What is the magnitude of the truck on the car? 2. Relevant equations Newton's 2nd and 3rd Laws 3. The attempt at a solution I can solve the problem once I know what the free body diagram looks like. I don't understand what to do with the 4500 N force. The problem states that 4500 N are "pushing against the ground." Does that mean I should a 4500 N force pointing in the same direction as gravity? Or does this force point in the direction of motion?