A satellite is orbiting the earth at 15000.km above the center of the earth, What speed is it going?

After the near spacecraft passed mathilde, on several occasions rocket propellant was expelled to adjust the spacecraft's momentum in order to follow a path that would approach the asteroid eros, the final destination for the mission. after getting close to eros, further small adjustments made the momentum just right to give a circular orbit of radius 45 km (45 × 10^3 m) around the asteroid. so much propellant had been used that the final mass of the spacecraft while in circular orbit around eros was only 545 kg. the spacecraft took 1.04 days to make one complete circular orbit around eros. calculate what the mass of eros must be.

Atrain departs from its station at a constant acceleration of 5 m/s. what is the speed of the train at the end of 20s?

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