Which of the following quantities are always zero in a simple harmonic motion?
Direction of Force and acceleration is always same.
Therefore, it will always be Zero as Sin(0°) = 0
Direction of Velocity and displacement is same, so this expression will also be zero.
As direction of Force and acceleration is always opposite to Displacement. This means θ = 180.
∴ Sin180° = 0
∴ Cross product of Displacement with Force and displacement with acceleration will always be Zero.
Hence, all four options are correct