A block on a spring oscillates with period T. Decide whether the Assertion (A) about how often its kinetic energy repeats is true, and whether the trigonometric Reason (R) explains it.

• Assertion (A): The kinetic energy of a particle in SHM varies periodically with a period of T/2.
• Reason (R): For x = A cos(ωt + φ), the kinetic energy is proportional to sin²(ωt + φ), and sin² repeats every half period of the motion.