In a simple harmonic motion, which of the following quantities is always positive?

Step-by-step solution

In simple harmonic motion, the restoring force F and acceleration a are related by Newton's second law as F = m a . Taking the dot product of F and a , we get: F a = (m a ) a = m| a |^2 = ma^2 Since mass m is a positive quantity and the square of the magnitude of acceleration a^2 is always non-negative, their product is always positive (or zero at the mean position). For the other options: a r = (- ^2 r ) r = - ^2 r^2 0 F r = (-k r ) r = -k r^2 0 v r can be positive or negative depending on whether the particle is