Physics - SHM Question with Solution | TestHub

From the graph $y=A\cos \left(\frac{2\pi t}{T}\right)$: extremes at $t=0,\frac{T}{2},T$; mean position at $\frac{T}{4},\frac{3T}{4}$

At $t=\frac{T}{2}$ the particle is at an extreme, so $v=0$: (A) false

At $t=T$ it is at an extreme: $|a|={\omega }^{2}A$ is maximum. (B) true

At $t=\frac{3T}{4}$ it is at mean position: $F=0$. (C) true

At $t=\frac{T}{2}$, all energy is potential: PE = total energy. (D) true

Answer: (B), (C), (D)