Simple Harmonic Motion & wave important Short Question
Ans: Velocity is zero: In Simple Harmonic Motion when object moves towards extreme position then its velocity decreases and becomes zero at extreme position. The object is at rest for instant so the velocity is zero at extreme position. Acceleration is maximum: According to Hooke’s law F = -kx . Its means restoring force is maximum at extreme position. Newton’s second of motion tells us that acceleration is directly proportional to the force. So at extreme position when restoring force is maximum then acceleration is maximum.
Ans: According to Newton’s second law of motion, the acceleration of the body is given by F=ma, Its mean a ∝ F/m . This shows that when the mass of mass spring system is doubles then its acceleration becomes half.
Ans: When a ball is dropped from an altitude on a perfectly elastic surface then the motion is vibratory motion as well as oscillatory but not simple harmonic because the restoring force F is equal to mg which is a constant and F ∝ x, Which is an essential condition for S.H.M where in an oscillation the acceleration is proportional to the displacement.
Frequency of mass spring system is given by
This equation shows that frequency depends upon the mass and spring constant. Same masses are attached, which means mass is constant then spring constant will be different for both springs. As spring constant k is directly proportional to the frequency of mass spring system. So, the spring system which has greater mass comparatively, must have greater frequency. Hence mass spring system which have greater mass is vibrating faster.
Ans: When a body moves back and forth or to and fro about its mean position. This is called vibration or oscillation. Example: Motion of simple pendulum.
The acceleration of a body executing SHM is directly proportional to the displacement of the body from the mean position and is always directed towards the mean position.
Mathematically