If the total mechanical energy of a swinging pendulum is 75 J, and its mass is 5.0 kg, what is the maximum height reached?
Use g = 10 m/s2

Two forces produce equal torques on a door about the door hinge. the first force is applied at the midpoint of the door; the second force is applied at the doorknob. both forces are applied perpendicular to the door. which force has a greater magnitude?

Uppose we consider the system of the three capacitors as a single "equivalent" capacitor. given the charges of the three individual capacitors calculated in the previous part, find the total charge qtot for this equivalent capacitor. express your answer in terms of v and c.

In a classical model of the hydrogen atom, the electron moves around the proton in a circular orbit of radius 0.053 nm. what is the electron's orbital frequency? what is the effective current of the electron?