If you have to apply 40 n of force to a crowbar to lift a rock that weighs 400 n, what is the actual mechanical advantage of the crowbar?

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?