A rescue service company has asked to design and make a model of "Jaws-of-Life" that they will use during the situation as illustrated above.

Pressure $P$ applied to the input piston is transmitted equally.

$$P = \frac{F_1}{A_1} = \frac{F_2}{A_2}$$

where $F_1$ is input force, $A_1$ input area, $F_2$ output force, $A_2$ output area.

$$A_1 = \pi (0.005)^2 = \pi \times 2.5 \times 10^{-5} \approx 7.85 \times 10^{-5} \ \mathrm{m}^2$$

Output piston radius $r_2 = 1.5$ cm $= 0.015$ m, so $A_2 = \pi r_2^2$.

$$A_2 = \pi (0.015)^2 = \pi \times 2.25 \times 10^{-4} \approx 7.07 \times 10^{-4} \ \mathrm{m}^2$$

$$F_2 = F_1 \times MA = 150 \times 9 = 1350 \ \mathrm{N}$$

The model exerts a spreading force of 1350 N on the car door.

1350 N