BRAVO! That is correct. The pressure in the hoist piston must be
P = W/A P = Mg / A
P = [(1000 kg)(9.8 m/s2)] / [ R2 ]
P = [(1000 kg)(9.8 m/s2)] / [ (10 cm)2 ]
The pressure in the hydraulic pump is
P = F / A P = F / [ r2 ]
P = F / [ (1 cm)2 ]
According to Pascal's Principle, these two pressures are the same
F / [ (1 cm)2 ] = [(1000 kg)(9.8 m/s2)] / [ (10 cm)2 ] F = [ (1 cm)2 ] [(1000 kg)(9.8 m/s2)] / [ (10 cm)2 ]
F = [ (1 cm)2 ] [(1000 kg)(9.8 m/s2)] / [ (10 cm)2 ]
F = [ (1 )2 ] [(1000 kg)(9.8 m/s2)] / [ (10 )2 ]
F = [(1000 kg)(9.8 m/s2)] / [ (100 )]
F = 98 N
For comparison, remember the weight of the car is
W = M g = (1000 kg)(9.8 m/s2) = 9,800 N This hydraulic hoist reduces the force necessary to lift the car by a factor of 100!
(c) 2000, Doug Davis; all rights reserved.