# Need help with vector dynamics problems

1. Nov 1, 2004

### krypt0nite

1) What is the maximum acceleration a car can undergo on a level ground if the static coefficient of friction between the tires and the ground is 0.55?

I have no idea on how to start this problem. It seems there is not enough information.

2) A city planner is working on the redesign of a hilly portion of a city. An important consideration is how steep the roads can be so that even small cars can get up the hills without slowing down. It is given that a particular small car, with a mass of 1000kg can accelerate on the level from rest to 14m/s in 8.0s. Using this figure, calculate the maximum steepness of a hill.

If you guys can help me start this problem, i should be able to finish it on my own.

2. Nov 2, 2004

### nelufar

In case of your first problem,you know that the maximum force is propotional to normal force and for static friction it is given as:
$$F_{max} ={\mu}_{s} * N$$
and
$$F_{max} = m * a$$
$$N = m * g$$
putting these equations in the first one you can calculate maximum acceleration.