Which of the following quantities are always positive in a simple harmonic motion?

In a simple Harmonic motion, Force must be linearly proportional to the displacement.

Also, F = -kx

a = -ω2x


Direction of Force and acceleration is always same. So, the

dot product will become positive as for <90° ,is positive.

So this expression is positive.


Direction of velocity and displacement is same so the expression will also be positive.


Force is opposite to displacement.

Dot product will become negative as for >90° ,is negative

So, this expression is negative



Force is opposite to displacement so it will also be negative.

Therefore, the option a and b are correct.