A particle is in linear S.H.M. between two points A and B, 10 cm apart. Take the direction from A to B as the positive direction and give the signs of velocity, acceleration and force on the particle when it is.
(a) at the end A (b) at the end B,
(c) at the mid point of AB going towards A,
(d) at 2 cm away from B going towards A,
(e) at 3 cm away from A goiing towards B, and
(f) at 4 cm away from A going towards A.

Explanation

Here AB = 10 cm, P is the mean position and A and B are extreme positions of a particle.
At extreme position A, the particle is at rest momentarily, Hence, velocity is zero.
The acceleration will be positive as it is directed along positive direction. Force is also positive as it is directed along positive direction AP.
At extreme position B, velocity is again zero as teh particle is at rest.
Acceleration is negative as it is directed along Bp (negative direction). Force is also negative as the particle is directed along BP. When the particle is at P and going towards A, velocity is negative, acceleration and force are zero. When particle is at 2 cm away from B going towards A, A, velocity, acceleration, force are all negative.
When particle is at 3 cm away from A going towards B, B, velocity, acceleration, force are all positive.
When particle is 4 cm away from A going towards A, velocity is negative, but force and acceleration are positive.