Tire inflation to determine weight

AI Thread Summary
The discussion revolves around calculating the weight of an automobile based on tire inflation pressure and contact area. The correct formula to use is Pfluid = F/A, where the pressure is 1.85E+5 Pa and the contact area per tire is 0.0237 m². After correcting a mathematical error, the weight per tire is determined to be approximately 4384.5 N, leading to a total weight of 17538 N for the four tires combined. Participants emphasize the importance of showing work to identify errors and clarify that each tire supports a fraction of the car's weight. The calculations ultimately confirm the correct approach to solving the problem.
BooGTS
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Tire inflation to determine weight - solved

The problem goes as follows: he four tires of an automobile are inflated to a gauge pressure of 1.85E+5 Pa. Each tire has an area of 0.0237 m2 in contact with the ground. Determine the weight of the automobile.

But I've applied the Pfluid = F/A and it doesn't seem to pan out. I come up with 447 N per tire, which is wrong.
 
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Please show your working. It's hard to see where you've gone wrong if you don't show your working.
 
Then you done the arithmetic wrong: 2 x 10^5 times 2x 10^(-2)= 4 x 10^3 or 4000, not 400.
 
I worked on this problem forever before posting and figured it out in this little window on this site of all places. I'm sure it won't be my last tonight though... thanks for the response.

1. 1.85 x10^5 N/m^2 = (x/.0237m^2)

2. 1.85 x10^5 N x .0237 = 4384.5 N = x

3. 4384.5 N x 4 = 17538N =x
 
BooGTS said:
4384.5 N x 4 = 17538N =x

Look's good to me :smile:
 
BooGTS said:
The problem goes as follows: he four tires of an automobile are inflated to a gauge pressure of 1.85E+5 Pa. Each tire has an area of 0.0237 m2 in contact with the ground. Determine the weight of the automobile.

But I've applied the Pfluid = F/A and it doesn't seem to pan out. I come up with 447 N per tire, which is wrong.

As Halls of Ivy said, that looks like a simple mathematical error.

Don't forget each tyre only bears a fraction of the weight of the car. So after getting the force exerted by each tyre on the ground, you need to do something else to find the weight of the car.

EDIT : Ah, OK, you've already posted it, that's correct. :smile:
 
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