Hello!

I will help you with the solution to this question.

We have, t= 4s and a=5 cm

Displacement(y)= a sinwt

=>y = 5sin(2π/4)t = 5sin(πt/2)

Also, v= dy/dt

=> v= (d/dt)[5sin(πt/2)] = (5/2)[πcos(πt/2)]

Again, a= dv/dt

=> a=( -5π^2/2)[sin(πt/2)]

After 1s,

y= 5sin(π/2×1) = 5sin(π/2) = 5cm

v= 5πcos(πt/2) = 5×(22/7)× cos(π/2×1)= 0 cm/s

a=( -5π^2/4)sin(π/2×1) = - 5π^2/4 cm/s^2 .

If you find the above solution a little confusing due to the text, I am giving the google drive link of my handwritten answer(copy and paste the link in your browser to view it):-

https://drive.google.com/file/d/19b3hb9YR8OVzdIzI9eKV2PnU6cYA5nSl/view?usp=drivesdk

Hope I was able to help you!