Specific angular momentum (with respect to a planetary body) of a test mass that orbits a planet and accretion dosk Specific angular momentum of a test mass that orbits a planet and accretion dosk

(See attached file for full problem description with proper symbols) --- Q2a The specific angular momentum (with respect to a planetary body) of a test mass that orbits a planet at a distance r with angular speed is j = r2 (scalars). Show how this follows from the expression of the angular momentum of this test mass, J = r p (vectors), where p is the linear momentum of the test mass. (Note: J, r, p, in this latter expression are vectors, and denotes the vector product, while j,r and in the former are scalars, and denotes a simple multiplication) I have answered this question as follows, please advise if I have made a mistake and what I have done wrong. Thank you. a) Sta... click for more

Crescent moon in the western horizon

I'm having a hard time figuring out what time it is when a crescent moon appears in the western horizon. Does it change throughout the year. I thought it was around 3 and 5 pm, but then I see that it is just after the sunset. The sun sets at different times throughout the year. so my question is What time is it when a crescent moon apears in the western horizon? and why?

Why is it more difficult to notice the westward motions of the stars that are high in the sky than those that are near the horizon?

Why is it more difficult to notice the westward motions of the stars that are high in the sky than those that are near the horizon?

The Scientific Revolution

Why do you think it was so difficult for people to accept the heliocentric model in the 1600s? And what do you think was the impact of this model, once it was accepted?

Integration - Determine if the following statement is true or false. If false, explain why and give an example that shows it is false.

Determine if the following statement is true or false. If false, explain why and give an example that shows it is false. See attached file for full problem description.