放鬆的心靈音樂｜Relaxing Music • Sleep Music,Relaxing Music, Meditation Music★51

壓力的概念
1、物理壓力：指發生在兩個物體的接觸表面的作用力，或者是氣體對於固體和液體表面的垂直作用力，或者是液體對於固體表面的垂直作用力。習慣上，在力學和多數工程學科中，“壓力”一詞與物理學中的壓強同義。
產生機理：
固體表面的壓力通常是彈性形變的結果，一般屬於接觸力。液體和氣體表面的壓力通常是重力和分子運動的結果。
壓力的作用方向通常垂直於物體的接觸面。如果觀測到壓力的作用方向與接觸面並不垂直，通常是由於壓力和摩擦力共同作用的結果。
2、心理壓力：壓力是心理壓力源和心理壓力反應共同構成的一種認知和行為體驗過程。壓力（stress）是一個外來詞，來源於拉丁文“stringere”，原意是痛苦。
現在所寫的單詞是“distress（悲痛、窮困）”的縮寫。有“緊張、壓力、強調”等意思，壓力會影響人們的身心健康，早已被公認。心理學家漢斯·塞爾斯（HanSelye）是第一個使用術語“stress（壓力）”的人。
壓力與重力：
1、壓力是由於相互接觸的兩個物體互相擠壓發生形變而產生的，按照力的性質劃分，壓力屬於彈力；重力是由於地面附近的物體受到地球的吸引作用而產生的。
2、壓力的方向沒有固定的指向，但始終和受力物體的接觸面相垂直。 （因為接觸面可能是水平的，也可能是豎直或傾斜的）重力有固定的指向，總是豎直向下。
3、壓力可以由重力產生也可以與重力無關。當物體放在水平面上且無其他外力作用時，壓力與重力大小相等。當物體放在斜面上時，壓力小於重力。當物體被壓在豎直面上時，壓力與重力完全無關。當物體被舉起且壓在天花板上時，重力削弱壓力的作用。
5、壓力的作用點在物體受力面上，重力的作用點在物體重心，規則的均勻的幾何體的重心在物體的幾何中心。
力可以使物體產生形變。例如，用木棒從各個角擠壓麵團，可看到，當木棒離開後，麵團上留下一個個的凹坑，這種使麵團發生凹陷形變的力為壓力。

stress concept
1. Physical pressure: refers to the force that occurs on the contact surfaces of two objects, or the vertical force of a gas on the surface of a solid and a liquid, or the vertical force of a liquid on the surface of a solid. Traditionally, in mechanics and most engineering disciplines, the word "pressure" is synonymous with pressure in physics.
Generation mechanism:
The pressure on a solid surface is usually the result of elastic deformation and is generally a contact force. The pressure on the surfaces of liquids and gases is usually the result of gravity and molecular motion.
The direction of action of the pressure is usually perpendicular to the contact surface of the object. If pressure is observed to act in a direction that is not perpendicular to the contact surface, it is usually due to the combined effect of pressure and friction.
2. Psychological stress: Stress is a cognitive and behavioral experience process composed of psychological stressors and psychological stress responses. Stress is a foreign word derived from the Latin "stringere", which means pain.
The word now written is an acronym for "distress". It has the meanings of "tension, stress, stress", etc. It has long been recognized that stress can affect people's physical and mental health. Psychologist Han Selye was the first to use the term "stress".
Pressure and Gravity:
1. Pressure is produced by the extrusion and deformation of two objects in contact with each other. According to the nature of force, pressure belongs to elastic force; gravity is produced by the attraction of objects near the ground by the earth.
2. The direction of the pressure has no fixed direction, but it is always perpendicular to the contact surface of the stressed object. (Because the contact surface may be horizontal, vertical or inclined) Gravity has a fixed direction, always straight down.
3. Pressure can be generated by gravity or independent of gravity. When an object is placed on a level surface and no other external force acts, the pressure and gravity are equal in magnitude. When an object is placed on an incline, the pressure is less than gravity. When an object is pressed against a vertical surface, the pressure is completely independent of gravity. When an object is lifted and pressed against the ceiling, gravity weakens the effect of pressure.
5. The action point of pressure is on the force-bearing surface of the object, the action point of gravity is at the center of gravity of the object, and the center of gravity of the regular and uniform geometry is at the geometric center of the object.
Forces can deform objects. For example, using a wooden stick to squeeze the dough from all corners, it can be seen that when the wooden stick leaves, there are pits left on the dough, and the force that makes the dough dent and deform is pressure.