I didn't learn to do this properly so please help me and explain it clearly.

The current in amps in an ac circuit containing a resistance is given by i = 1.5 sin ωt where ω = angular velocity, t = time in seconds, and ωt = angle in radians. If the angular velocity ω = 300 rad/s

(a) Find i in milliamps when t = 2.0 ms

(b) Find the angle ωt in radians between 0 and 2π rad when i = mA

How do I go about doing this problem? Please explain clearly, thanks.