Finding net force on a car in mud without knowing its mass

[*sperry*]

1. A car is moving to the right with velocity 22.2 m/s when it enters an area having a soft, muddy surface. If the soft surface is only 25.0 m long, but the car slows to 15.3 m/s while going through the muddy area, answer the following:

A) What length of time (in seconds) was the car in the muddy area?

B) What acceleration did the car experience?

C) What was the value of the net force causing the acceleration?



2. 2d/vi+vf=ΔT
a=vf^2-vi^2/2d
Fnet=ma



3. A) ΔT=1.33s

B) a=-5.19m/s

C) Answer is apparently -6220 N but I don't know how to get it.



I have trouble getting C. I don't have a mass so I'm not sure how to find Fnet. I feel like I'm missing a relationship here.

 

[Doc Al]

Without the mass you cannot determine the force. Did you leave any information out of the problem statement?