# Mass of the Car?

1. Oct 2, 2014

### math989

• Warning! Posting template must be used for homework questions.
A race car exerts 19,454 N while the car travels at a constant speed of 201 mph, 91.36 m/s. What is the mass of the car?

F=m(a)
I have no idea how to start this problem; I labelled out my given info but i do not know how to incorporate it into my equation. At first i thought to use kinematic equations but that did not work.

2. Oct 2, 2014

### SteamKing

Staff Emeritus
If by "A race car exerts 19,454 N ...", the problem means this is the normal force acting on the road surface due to the gravitational attraction between the earth and the car, how would that affect the use of your formula?

3. Oct 2, 2014

### math989

Does that indicate that i have to use the gravity of the earth for the "a" variable and rearrange the equation so that it is m=f/g?

4. Oct 2, 2014

### SteamKing

Staff Emeritus
Well, the car is traveling at constant speed, so there is no acceleration down the track. It's a simple calculation, so why not try it?

5. Oct 2, 2014

### Simon Bridge

The 19454N is the weight of the car.
What is the difference between weight and mass?

6. Oct 2, 2014

### Sheetal Sharma

Mass - simply measurement of amount of matter in a body, it is expressed in m or M.
Weight - Measurement of the amount of force used by gravity to pull that matter, it is expressed in W. Weight is mass multiplied by the acceleration of gravity.

Formula: W = mg
where, W - Weight
m - Mass
g - gravitational acceleration