1. A hydraulic lift office chair has its seat attached to a piston with an area of 11.2 cm2. The chair is raised by exerting force on another piston, with an area of 4.12 cm2. If a person sitting on the chair exerts a downward force of 219 N, what force needs to be exerted on the small piston to lift the seat?
Answer: a= 11.2 cm2 A= 4.12 cm2 f= 219 N F= 80.56 N
F= fA / a ; (219 N) (4.12 cm2 ) / 11.2 cm2 = 80.56 N
F/ f = 80.56 N/ 219 N = 0.37
A/ a = 4.12 cm2 / 11.2 cm2 = 0.37
2. In changing a tire, a hydraulic jack lifts 7468 N on its large piston, which has an area of 28.27 cm2. How much force must be exerted …show more content…
An engine shop uses a lift to raise a 1784 N engine. The lift has a large piston with an area of 76.32 cm2. To raise the lift, force is exerted on a small piston with an area of 12.56 cm2. What force must be exerted to raise the lift?
Answer: F= 1784 N
A= 76.32 …show more content…
In a newly designed car with a hydraulic braking system, a force of 85 N is applied to one of the master cylinders, which has an area of 8.1 cm2. The master cylinder is connected to one brake piston, which exerts a force of 296 N. What is the area of the brake piston?
Answer: f= 85 N
A= 8.1 cm2
F= 296 N
A= 28.21 cm2
Solution:
A= Fa/ f ; (296 N)(8.1 cm2 ) / 85 N = 28.21 cm2
F/ f = 296 N / 85 N = 3.49
A/ a = 28.21 cm2 / 8.1 cm2 = 3.49
4. A mechanic uses a hydraulic car jack to lift the front end of a car to change the oil. The jack she uses exerts 8915 N of force from the larger piston. To pump the jack, she exerts 444 N of force on the small piston, which has an area of 3.14 cm2. What is the area of the large piston?
Answer: A= 63.05 cm2
a= 3.14 cm2
F= 8915 N
f= 444 N
Solution:
A= Fa/ f ; (8915 N)(3.14 cm2 ) / 444 N = 63.05