How long does it take a 2.5 KW weightlifter who to lift 250 kg a height of 2.0 m?

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.

Which statement describes the formation of our sun? a disk formed of long trails of stars coiled into a spiral. it formed an elliptical flattened disk. heat and gases contracted within a nebula. gravity pushed stars away from a center core.

Ideal meters problem. what internal resistance is ideal for a voltmeter? what internal resistance is ideal for an ammeter?