Thread: Math problem

We have alternating current in the United Sates. This electric current alternates with a frequency of 60 cycles per second. Suppose that at time of t = 0.02 seconds, the current is at its maximum of l = 5 amperes. If the current varies sinusoidally over time, write and expression l(t) for the current as as function of time in t in seconds.

Anybody? I need to show work too.

Originally Posted by Airjunkie

We have alternating current in the United Sates. This electric current alternates with a frequency of 60 cycles per second. Suppose that at time of t = 0.02 seconds, the current is at its maximum of l = 5 amperes. If the current varies sinusoidally over time, write and expression l(t) for the current as as function of time in t in seconds.

Anybody? I need to show work too.

I is a sinusoidal function so you can start with


We know that f = 60 Hz, so




At t = 0.02 s the current is at its maximum, thus we know that




So


And finally, , so


-Dan