Question

Q5 Q19 Choose the correct formula for the displacement d from the rest position of the object attached to the spring at time t.

Answer 1

t=0, d=0 so ans B is wrong

t=0, dd/dt <0 as it is propelled downward so ans C is wrong

ang vel = 2
`\pi` / period

= 2
`\pi` / 4.5

= 4
`\pi` / 9

so D is the correct answer