A mass on a spring vibrates horizontally on a smooth level surface (see the figure). Its equation of motion is x(t) = 4 cos t, where t is in seconds and x is in centimeters.
![1507_A mass on a spring vibrates horizontally.png](https://secure.tutorsglobe.com/CMSImages/1507_A%20mass%20on%20a%20spring%20vibrates%20horizontally.png)
a. Find the velocity and acceleration at time t.
b. Find the position, velocity, and acceleration of the mass at time t = 5 π/6.
c. In what direction is it moving at that time?