Pressure problem

1. Jan 15, 2016

Nanu Nana

1. The problem statement, all variables and given/known data
A car is put into a garage higher by a hydraulic lift. How large should be the surface on which the vehicle rest if you to lift a vehicle of 1000kg higher with overpressure of 1 atm?

2. Relevant equations

Pabsolue pressure = P atmos + P relative
P=F/A
F=m xa

3. The attempt at a solution
P absolute = 101325 Pa +101325 pa
1000kg x9.81 m/s^2 / (A) = 202650
1000kg x 9.81 =202650A
A= 1000x9.81 /202650
A=0.04840 m^2

But the answer should be 9,682.10-2 m 2

2. Jan 15, 2016

Dr. Courtney

It's always a hint when your answer is off by very close to a factor of two.

3. Jan 15, 2016

Nanu Nana

I don't understand

4. Jan 15, 2016

J Hann

What would be the net force produced using a closed cylinder containing air at atmospheric pressure?

5. Jan 15, 2016

haruspex

Is there a vacuum above the car and the platform it stands on?

6. Jan 17, 2016

Nanu Nana

No there is no vacuum

7. Jan 17, 2016

haruspex

Right. So what force have you overlooked?

8. Jan 17, 2016

Nanu Nana

Thank you for helpful videos

9. Jan 17, 2016

Nanu Nana

Force of gravity?

10. Jan 17, 2016

haruspex

What force is acting on the platform that would not act on it under a vacuum?