Velocity of SHM Object at t=0.10s

[Jdy]

Homework Statement

At time t, the velocity of v of an object undergoing simple harmonic motion at the end of a spring is given by the formula below. here m is mass of the object (in g), k is a constant depending on the spring (in g/s squared), a is the maximum distance the object moves and t is time (in s).

t=0.10s
m= 36.0g
k= 400g/s][2]
A= 5.0 cm

Homework Equations

v=A*√K/m*cos(√K/m *t)

The Attempt at a Solution

 

[gneill]

You have a formula for the velocity and the values of all the variables. So what's your attempt at a solution?