At one particular moment, a 15.0 kg toboggan is moving over a horizontal surface of snow at 4.40 m/s. After 7.50 s have elapsed, the toboggan stops. Use a momentum approach to find the magnitude of the average friction force (in N) acting on the toboggan while it was moving.

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?