calculate the force necessary to keep a mass of 2 kg moving on a circular path of radius 0.2 m with a period of 0.5 second. what is the direction of force

Aproton is projected toward a fixed nucleus of charge +ze with velocity vo. initially the two particles are very far apart. when the proton is a distance r from the nucleus its velocity has decreased to 1/2vo. how far from the nucleus will the proton be when its velocity has dropped to 1/4vo?

In order for the bug to fly through the air a force has to push the bug forward. identify this force. how does the bug produce

To do work, this truck uses energy stored in chemical fuel and an electrical battery. how much total energy does this truck put out?