Answer
a. 33.4 Hz
b. 0.990 A
c. V = 33.6 sin(210t) in volts
Work Step by Step
a.) I(t) = 1.40 sin(210t)
$I(t) = I_{0} sin(2πft)$
$2πf = 210 \frac{rad}{s}$ and $I_{0} = 1.40 A$
$f = \frac{210 \frac{rad}{s}}{2π rad}$ = 33.4 $\frac{1}{s}$ = 33.4 Hz
b.) $ I_{0} = 1.40 A$, so $I_{rms} = \frac{I_{0}}{\sqrt 2}$
$I_{rms} = \frac{1.40}{\sqrt 2} = 0.9899 A \approx 0.990 A$
c.) $V = IR = [1.40 sin(210t)] \times 24 Ω = 33.6 sin(210t)$ in volts