How do you do a, b, and c of #5? i'm not sure how.

Ateam of astronauts is on a mission to land on and explore a large asteroid. in addition to collecting samples and performing experiments, one of their tasks is to demonstrate the concept of the escape speed by throwing rocks straight up at various initial speeds. with what minimum initial speed vesc will the rocks need to be thrown in order for them never to "fall" back to the asteroid? assume that the asteroid is approximately spherical, with an average density p 3.84 x108 g/m3 and volume v 2.17 x 1012 m3 recall that the universal gravitational constant is g 6.67 x 10-11 n m2/kg2

Is there a point between a 10 nc charge and a 20 nc charge at which the electric field is zero?

As microwave light travels through a liquid, it moves at a speed of 2.2 x 108 m/s. if the frequency of this light wave is 1.1 x 108 hz, what is the wavelength of this microwave?