1.
A hydraulic system is used to lift a 2000 kg vehicle in an auto garage. If the vehicle sits on a piston of area 0.5 square meter, and a force is applied to a piston of area 0.03 square meters, what is the minimum force that must be applied to lift the vehicle?
Correct Answer
C. 1176 N
Explanation
The force exerted on the larger piston can be calculated using the formula: force = pressure x area. The pressure exerted on the larger piston is the same as the pressure exerted on the smaller piston, as they are connected by a hydraulic fluid. Therefore, the force exerted on the larger piston is (force on smaller piston) x (area of larger piston / area of smaller piston). Plugging in the values given, we get: force = (force on smaller piston) x (0.5 square meters / 0.03 square meters) = (force on smaller piston) x 16.67. Solving for the force on the smaller piston, we find that it must be at least 1176 N in order to lift the vehicle.
2.
Pascal's law applies to gases as well.
Correct Answer
A. True
Explanation
Pascal's law states that a change in pressure applied to an enclosed fluid is transmitted undiminished to all portions of the fluid and to the walls of its container. This law applies to both liquids and gases, as they are both considered fluids. Therefore, the correct answer is true.
3.
Which of the following statements is true?
Correct Answer
A. If the second area is greater than the first area, then the second force exerted on the system should be greater than the first force.
Explanation
The correct answer is that if the second area is greater than the first area, then the second force exerted on the system should be greater than the first force. This is because pressure is equal to force divided by area, so if the area increases while the force remains the same, the pressure decreases. Therefore, in order to maintain the same pressure, the force must increase when the area increases. This is consistent with Pascal's principle, which states that pressure is transmitted equally in all directions in a confined fluid.
4.
Which of the following is true about the hydraulic system?
Correct Answer
C. The pressure exerted on a small piston is equal to that on the larger piston.
Explanation
In a hydraulic system, the pressure exerted on a small piston is equal to that on the larger piston. This is because the pressure in a fluid is transmitted equally in all directions. Therefore, the force applied to the small piston is magnified by the ratio of the areas of the small and large pistons, resulting in equal pressure on both pistons. This principle allows for the amplification of force in hydraulic systems, making them useful in various applications such as car brakes and construction equipment.
5.
Which of the following is the application of hydraulic system?
Correct Answer
C. Cardiovascular system and jacks
Explanation
The application of hydraulic systems includes the cardiovascular system and jacks. Hydraulic systems are used in the cardiovascular system to control blood flow and pressure. They are also used in jacks to lift heavy objects by applying force through the use of fluids.
6.
A barber raises his customer’s chair by applying a force of 150N to a hydraulic piston of area 0.01 m2. If the chair is attached to a piston of area 0.1 m2, how massive a customer can the chair raise? Assume the chair itself has a mass of 5 kg.
Correct Answer
A. 148 kg
Explanation
The force applied by the barber to raise the chair is equal to the force exerted by the chair on the customer. The force applied by the barber is calculated by multiplying the pressure exerted by the hydraulic piston (force/area) by the area of the piston the barber is pushing on. The force exerted by the chair on the customer is calculated by multiplying the pressure exerted by the hydraulic piston (force/area) by the area of the piston attached to the chair. Since the areas cancel out, the force applied by the barber is equal to the force exerted by the chair on the customer. Therefore, the chair can raise a customer with a mass of 148 kg.
7.
Which is the practical application of the Pascal's law?
Correct Answer
A. Hydraulic Press
Explanation
The practical application of Pascal's law can be seen in a hydraulic press. Pascal's law states that when pressure is applied to a fluid in a confined space, the pressure is transmitted equally in all directions. In a hydraulic press, a small force is applied to a small piston, which creates a pressure in the fluid. This pressure is then transmitted to a larger piston, which exerts a much greater force. This principle allows the hydraulic press to generate a large amount of force, making it useful for applications such as pressing, bending, and forming materials.
8.
When was Pascal's Law discovered?
Correct Answer
B. 1653
Explanation
Pascal's Law was discovered in 1653.
9.
The pressure at the bottom of the tank that has liquid doesn't depend on what?
Correct Answer
C. Area of the bottom
Explanation
The pressure at the bottom of the tank that has liquid doesn't depend on the area of the bottom. The pressure at the bottom of a liquid is determined by the height of the column of liquid above it and the density of the liquid. The area of the bottom does not affect the pressure because pressure is force per unit area, and the force exerted by the liquid depends on its weight, which is determined by the height of the column and the density of the liquid. The area of the bottom only affects the total force exerted by the liquid, not the pressure.
10.
According to Archimedes' Law, the loss of weight in the body in the liquid is equal to.
Correct Answer
D. Weight of liquid displaced
Explanation
According to Archimedes' Law, the loss of weight in a body submerged in a liquid is equal to the weight of the liquid displaced. This means that when an object is placed in a liquid, it will experience a decrease in weight equal to the weight of the liquid that is pushed aside or displaced by the object. This principle explains why objects float or sink in a liquid, as the buoyant force exerted on the object is equal to the weight of the liquid it displaces.