# Pressure on tyres of a vehicle question - Calculating weight

1. Oct 1, 2013

### Molly1235

1. The problem statement, all variables and given/known data

The pressure in the tyres of a vehicle is 280 kPa. The contact area of each of the four tyres on the ground is 0.012m^2. Calculate the weight of the vehicle.

2. Relevant equations

Force = Pressure x Area

3. The attempt at a solution

280 kPa = 2800000 Pa

Force = 2800000 x 0.012 = 33,600N

Am I right in assuming that this is the weight of one tyre, so you have to multiply this by 4 to get the force of the whole vehicle on the ground??

I think I've gone completely wrong here so would be grateful for some help!

Thanks :-)

2. Oct 1, 2013

### SteamKing

Staff Emeritus
Double check your conversion of 280 kPa to Pa.

3. Oct 1, 2013

### Molly1235

Oops - wouldn't it be 280,000 Pa?

4. Oct 1, 2013

### I like Serena

Yep!

That looks better!

5. Oct 1, 2013

### Molly1235

So my method was correct??

6. Oct 1, 2013

Yes.

7. Oct 1, 2013

### Molly1235

Yay! Thank you very much!!