Two students have volunteered to explore the galaxy in a spaceship. As they travel through space, they measure the magnitude of the gravitational force between their spaceship and the earth they find that the gravitational force on the spaceship is-

Aball tossed vertically upward from the ground next to a building passes the bottom of a window 1.8 s after being tossed and passes the top of the window 0.20 s later. the window is 2.0 m high from top to bottom. what was the ball's initial velocity? the unit vector j^ is directed upward. how far is the bottom of the window from the launch position? how high does the ball rise above the launch position?

Humidity is to blame for that muggy, steamy feeling you experience on some hot summer days. what gas in the atmosphere causes humidity? a) oxygen b) hydrogen c) nitrogen d) water vapor

Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space? the cloud is extremely hot. the cloud is visible primarily because it reflects light from nearby stars. the cloud is cool and lies between you and a hot star. the cloud is cool and very dense, so that you cannot see any objects that lie behind it.