Question

Physics problem: piston? The piston of a hydraulic automobile lift is 0.300 m in diameter. 1. What gauge pressure, in pascals, is required to lift a car with a mass of 1200 kg?

Answer 1

Given:
d = 0.3 m, piston diameter
m = 1200 kg, mass to be lifted

The piston area is
A = (n/4)*(0.3 m)² = 0.0707 m².

Let p (Pa) be the required piston pressure.
Then (p N/m²)*(0.0707 m²) = (1200 kg)*(9.8 m/s²)
p = 1.6637 x 10⁵ Pa = 166.4 kPa

Answer: 1.664 x 10⁵ Pa or 166.4 kPa

Answer 2

Pressure is given by:
P=F/A
force=1200*10=12000 N
Area=pi*r^2=3.14*0.15^2
=0.07065 m^2
Thus;
P=12000/0.7065
P=169,851.38 N/m^2
but
1 N/m^2=1 Pa
thus our pressure is:
169,851.38 Pa