压强与浮力 知识小结(国外英文资料).docVIP

压强与浮力 知识小结(国外英文资料) The thirteenth chapter, stress and pressure review outline First, the pressure and pressure of solids 1, pressure: The definition of vertical compression on the surface of objects called pressure force. The pressure is caused by gravity, usually put the object on the table, if the object is not affected by the other force, pressure F = the gravity of the object G It can change the direction of the size of solid delivery pressure. 2. Study the factors that affect the effect of stress: Text books a and B: the force area at the same time, the greater the pressure the pressure effect is more obvious. The pressure effect is more obvious when the pressure is the same and the stress area is smaller. Summarizing these two experiments, the conclusion is that the effect of pressure is related to the pressure and the force area. In this experiment, the control variable method was adopted. Contrast method 3, pressure: Definition: the pressure on a unit area of an object is called pressure. The physical meaning: pressure is the physical quantities of the effect of pressure The formula of p=F/ S in which the amount of units are: P: Pascal (Pa); F: Newton (N): S (M2) 2 meters. When A uses this formula to calculate the pressure, the key is to find the pressure F (general F=G=mg) and the force area S (the force area should pay attention to the contact part of the two objects). B exception: for the straight column on the table (such as cylinder, cube, long body) on the desktop pressure P GH p= I know the pressure unit of Pa: a newspaper on the table when the flat pressure is about 0.5Pa. When adults stand, the pressure on the ground is approximately 1.5 * 104Pa. It says when a man stands, the pressure on his feet is 1.5 * 104N per square meter The application: when the pressure is constant, the pressure can be reduced by methods such as increasing the force area: rail sleeper, tanks, tracked bag with wide. You can also increase the pressure by reducing the force