A small rock is thrown straight up with initial speed V0 from the edge of the roof of a building with height H. The rock travels upward and then downward to the ground at the base of the building. Let +y be upward, and neglect air resistance. (a) For the rock's motion from the roof to the ground, what is the vertical component Vav-y of its average velocity? Is this quantity positive or negative? Explain. (b) What does your expression for Vav-y give in the limit that H is zero? Explain. (c) Show that your result in part (a) agrees with Eq. (2.10).

Imagine you are riding on a yacht in the ocean and traveling at 20 mph. you then hit a golf ball at 100 mph from the deck of the yacht. you see the ball move away from you at 100mph, while a person standing on a near by beach would observe your golf ball traveling at 120 mph (20 mph + 100 mph). now imagine you are aboard the hermes spacecraft traveling at 0.1c (1/10 the speed of light) past mars and shine a laser from the front of the ship. you would see the light traveling at c (the speed of light) away from your ship. according to einstein’s special relativity, how fast will a person on mars observe the light to be traveling? a) 0.1c (1/10 the speed of light) b) c (the speed of light) c)1.1c (c+0.1c)