Pressure：练习题

A rectangular block of weight \( 60 \text{ N} \) has dimensions \( 0.2 \text{ m} \times 0.3 \text{ m} \times 0.5 \text{ m} \). What is the minimum pressure the block can exert when placed on a flat horizontal surface?

A rectangular metal block is completely submerged in a container of water. Which statement best explains why there is a net upward force (upthrust) acting on the block?

The diagram shows a lever system connected to a hydraulic press. A downward force of \( 40 \text{ N} \) is applied at the end of the lever. What is the weight of the load that can be supported by the large piston?

The SI unit of pressure is the pascal (\( \text{Pa} \)). Which of the following is equivalent to \( 1 \text{ Pa} \)?

The diagram below shows a manometer used to measure the pressure of a gas supply. If the liquid used is oil with a density of \( 800 \text{ kg/m}^3 \) and the height difference between the two columns is \( 20 \text{ cm} \), calculate the pressure difference between the gas and the atmosphere. (Take \( g = 10 \text{ m/s}^2 \))

The atmospheric pressure at sea level is \( 760 \text{ mm Hg} \). A mercury barometer is carried to the top of a hill where the atmospheric pressure is \( 95 \text{ kPa} \). Given that the density of mercury is \( 13600 \text{ kg/m}^3 \), calculate the height of the mercury column in the barometer at the top of the hill. (Take \( g = 10 \text{ N/kg} \))

A vertical cylinder with a base area of \( 0.04 \text{ m}^2 \) contains a gas trapped by a piston of mass \( 5.0 \text{ kg} \). If the atmospheric pressure is \( 1.013 \times 10^5 \text{ Pa} \), calculate the absolute pressure of the trapped gas. (Take \( g = 10 \text{ N/kg} \))

A hydraulic jack is used to lift a car. The small piston has a cross-sectional area of \( 5.0 \text{ cm}^2 \) and the large piston has an area of \( 125 \text{ cm}^2 \). If a force of \( 60 \text{ N} \) is applied to the small piston, determine the maximum weight that can be supported by the large piston, assuming no energy losses.

A solid rectangular block has a mass of \( 5.0 \text{ kg} \). Its dimensions are as shown in the diagram.

(a) Calculate the weight of the block. (Take \( g = 10 \text{ m/s}^2 \))

(b) The block is placed on a horizontal table. Determine the maximum pressure it can exert on the table.

(c) Determine the minimum pressure the block can exert on the table by changing its orientation.

A rectangular wooden block has dimensions of \( 0.20 \text{ m} \times 0.10 \text{ m} \times 0.05 \text{ m} \) and a mass of \( 0.60 \text{ kg} \).

(a) Calculate the density of the wood in \( \text{kg/m}^3 \).
(b) The block is placed on a horizontal table. Determine the maximum pressure it can exert on the table surface.
(c) Calculate the minimum pressure it can exert on the table surface. (Take \( g = 10 \text{ N/kg} \))