1. What is Sound? Sound is a form of energy which produces a sensation of hearing in our ears. Sound is produced by vibrating objects. Examples include vibrating tuning fork, vocal cords in humans, bells, musical instruments, etc. Vibration: Rapid to-and-fro (back and forth) motion of an object. Short Question: Can sound be produced without vibration? Answer: No, sound cannot be produced without vibration. 2. Medium of Sound The substance through which sound travels is called a medium . Sound can travel through solids, liquids, and gases but cannot travel through vacuum . Process of Sound Propagation: When an object vibrates, it makes the air particles around it vibrate. These air particles move back and forth from their original (rest) position. The vibrating air particles push nearby air particles. This causes the nearby particles to also start vibrating. In this way, vibrations pass from one particle to another. This process continues through the medi...
Work Work is done when a force causes displacement in the direction of the applied force. Condition for work done: Force should be applied on the body. Body should be displaced. Work done in moving a body is equal to the product of force and displacement of the body in the direction of the force. Formula: W = F × s SI Unit of Work: Joule (J) = N·m 1 Joule: 1 J is the amount of work done on an object when a force of 1 N displaces it by 1 m along the line of action of the force. 1 Joule (J) = 1 Newton (N) × 1 metre (m) Work done by a force can be either positive or negative. Work done is negative when the force acts opposite to the direction of displacement. Work done is positive when the force is in the direction of displacement. Energy The energy possessed by an object is its capacity for doing work. S.I. unit of energy is Joule (J). 1 Joule of energy is the amount of energy required to do 1 Joule of work. ...