Physics Exam Review
I. Pascal’s Principle:
✓ The pressure applied on one part of container with fluid is transmitted equally in all directions.
✓ Pressure on one side is equal to the pressure on the other side of hydraulic press and lift
Pascal Law:
“The pressure exerted anywhere in a mass of confined liquid is transmitted undiminished in all directions throughout the liquid.”
Equation for Pascal’s Principle:
P1 = P2
F1 = F2
A1 A2
Problems:
1. The large piston in a hydraulic lift has an area of 250 cm2. What force must be applied to the small piston with an area of 25 cm2 in order to raise a car of mass 1500 kg?
2. A trash compactor pushes down with a force of 500 N on a 3 cm2 input piston, causing a force of 30,000 N to crush the trash. What is the area of the output piston that crushes the trash?
3. When the button of a trash compactor is pushed, a force of 350 N pushes down on a 1.3 cm2 input piston, creating a force of 22,076 N to crush the trash. What is the area of the piston that crushes the trash?
4. Mr. Sharlow is raising a 2000kg car on his hydraulic lift. If the area of the input piston is 9cm2, while the area of the output piston is 630 cm2, what force must be exerted on the input piston to lift the car?
II. Buoyancy:
-apparent loss of weight of objects
✓ Buoyant force
- net upward force exerted by the fluid
- causes floatation > when FB is greater than the weight of the object
- constant throughout the same fluid
- increases when density of fluid increases
- equal to the difference of weight of object in air and weight of object in liquid
Problem:
1. The weight of the object is 3 N. It is placed in a tan of water. The water exerts 5 N net upward force on the object. Will the object float?
2. A block of metal weighs 5 N when suspended in air. When placed in water, it weighs 3 N. How much buoyant force acts
✓ The pressure applied on one part of container with fluid is transmitted equally in all directions.
✓ Pressure on one side is equal to the pressure on the other side of hydraulic press and lift
Pascal Law:
“The pressure exerted anywhere in a mass of confined liquid is transmitted undiminished in all directions throughout the liquid.”
Equation for Pascal’s Principle:
P1 = P2
F1 = F2
A1 A2
Problems:
1. The large piston in a hydraulic lift has an area of 250 cm2. What force must be applied to the small piston with an area of 25 cm2 in order to raise a car of mass 1500 kg?
2. A trash compactor pushes down with a force of 500 N on a 3 cm2 input piston, causing a force of 30,000 N to crush the trash. What is the area of the output piston that crushes the trash?
3. When the button of a trash compactor is pushed, a force of 350 N pushes down on a 1.3 cm2 input piston, creating a force of 22,076 N to crush the trash. What is the area of the piston that crushes the trash?
4. Mr. Sharlow is raising a 2000kg car on his hydraulic lift. If the area of the input piston is 9cm2, while the area of the output piston is 630 cm2, what force must be exerted on the input piston to lift the car?
II. Buoyancy:
-apparent loss of weight of objects
✓ Buoyant force
- net upward force exerted by the fluid
- causes floatation > when FB is greater than the weight of the object
- constant throughout the same fluid
- increases when density of fluid increases
- equal to the difference of weight of object in air and weight of object in liquid
Problem:
1. The weight of the object is 3 N. It is placed in a tan of water. The water exerts 5 N net upward force on the object. Will the object float?
2. A block of metal weighs 5 N when suspended in air. When placed in water, it weighs 3 N. How much buoyant force acts