Astudent gains 2.1 lb in two weeks. part a how many grams did he gain?

How much work would be needed to raise the payload from the surface of the moon (i. e., x = r) to an altitude of 5r miles above the surface of the moon (i. e., x = 6r)?

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.

True or false: the cycle of seasons on the earth is caused by the tilt of the earth on its axis toward and away from the sun.