Question

A particle is in linear simple harmonic motion between A and B, $10$cm apart (figure). Take the direction from A to B as the +ve direction.Which of the following statements is correct?

• A. The sign of acceleration and force on the particle when it is at A is negative.
• B. The sign of acceleration and force on the particle when it is at B is positive.
• C. The sign of velocity, acceleration and force on the particle when it is $3$ cm away from A going towards B are positive.
• D. The sign of velocity, acceleration and force on the particle when it is $4$ cm away from B going towards A are positive

Answer 1

The correct option is C The sign of velocity, acceleration and force on the particle when it is $3$ cm away from A going towards B are positive.

For $SHM$ :
Force on the particle $\propto$ $-x$
Similarly: Acceleration $\propto$ $-x$

Its mean velocity of the particle will increase when it comes toward the mean position from any extreme position.
Let P be the mean position and particle is at point R So RP will be negative according to question, therefore acceleration and force on the particle will be positive.

Option C