Solving for Normal Force between two objects

[Dyscalculiac]

Homework Statement

Your friend's car broke down. You push it to a repair shop 2.0 km away. You gently put your car's bumper against the broken car's bumper and accelerate to a speed of 2.5 m/s over the course of 1 min. If the broken car's mass is 1200 kg, what is the normal force between the two bumpers? And, If you maintain a speed of 2.5 what is the total time it takes to reach the repair shop?

Homework Equations

Fn=-mg and D=vt

The Attempt at a Solution

For the first answer I used the equation Fn=-mg to find the normal force. I got 11760N. For the second I used d=vt and got 5 seconds. The answer is 50N and 830 seconds. What am I missing??

 

[voko]

What does g have to do with the normal force between the bumpers?