How many joules of kinetic energy does a pendulum have when it has 100 joules of potential energy

What produces light and all other electromagnetic waves? a) the photoelectric phenomena b) heated metals c) charged particles d) radioactive samples (pls explain if you can : )

Prompta snowboarder stands at the top of a hill and decides to see if he can increase his speed on his next trip down the slope. describe one thing the snowboarder could do to incrlase his speed on the slope. explain why this would cause his speed toincrease relate one of newton's laws to this problem.

A-4.60 μc charge is moving at a constant speed of 6.80×105 m/s in the +x−direction relative to a reference frame. at the instant when the point charge is at the origin, what is the magnetic-field vector it produces at the following points.