At which location would an object’s weight be the greatest?
A. On Pluto
B. On Earth
C. On the Sun
D. On the Moon

The man fires an 80 g arrow so that it is moving at 80 m/s when it hits and embeds in a 8.0 kg block resting on ice. how far will the block slide on the ice before stopping? a 7.1 n friction force opposes its motion.

Idon’t quite understand this problem

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?