Please help: how do I determine the force constant of the spring? Show work please.

An observer that stands still as the electron moves by him, will observe

The graph describes the motion of an object. the object moves with from a to b. it from b to c. it moves with from c to d.

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 2.70 miss . you then use the resistor and capacitor to make a low-pass filter. what is the crossover frequency fc?