Answer:
926 N
Explanation:
Metric unit conversion:
R = 18 cm = 0.18 m
r = 5 cm = 0.05 m
The pressure exerted by the F = 12000N car on the wider arm would be ratio of the gravity over area
[tex]P = F/A = \frac{F}\pi R^2} = \frac{12000}{2*\pi*0.18^2} = 117892 Pa[/tex]
The pressure must be the same on the smaller pressure for it to be able to start lifting the car. We can calculate the force f acting on it:
[tex]f = Pa = P\pi r^2 = 117892 * \pi * 0.05^2 = 926 N[/tex]