physics
posted by y912f on .
how do i do this
A force of 230 N applied on a hydraulic lift raises an automobile weighing 6500 N. If the applied force is exerted on a 7.0 m^2 piston, what is the area of the piston beneath the automobile?
a. 2.0 * 10^2 m^2
b. 4.0 m^2
c. 0.25 m^2
d. 0.0050 m^2
A water bed that is 1.5 m wide and 2.5 m long weighs 1055 N. Assuming the entire lower surface of the bed is in contact with the floor, what is the pressure the bed exerts on the floor?
a. 250 Pa
b. 260 Pa
c. 270 Pa
d. 280 Pa
thanks for any help!

Use the principal that the pressure throughout the fluid is equal. The force that is applied by (or to) a piston is therefore proportional to its area. The automobile piston area must be larger by a factor 6500/230
The answer to the secoind proboem is water weight/water bed area. Round off to two significant figures and you will agree with one of those answers 
c.270

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