What force is required to accelerate a body of mass 20.0 kg from 3.00 m/s to 9.00 m/s in 10.0 s?

The summit of chimborazo, in ecuador, which is at a distance of about 6,384 km from the earth's center. the bottom of the mariana trench, in the western pacific ocean, which is nearly 6,370 km from the center of the earth. on the surface of earth on the equator line.

In which of the following is positive work done by a person on a suitcase

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?