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.