A 15kg person falls with a force of 147N. But when measured we find the person is only accelerating at 5m/s/s. How much air friction must be acting on the person?

You have a resistor and a capacitor of unknown values. first, you charge the capacitor and discharge it through the resistor. by monitoring the capacitor voltage on an oscilloscope, you see that the voltage decays to half its initial value in 3.00 ms . you then use the resistor and capacitor to make a low-pass filter. what is the crossover frequency fc?