What type of chemical reaction occurs when beryllium (Be) combines with oxygen (O2) to form beryllium oxide (Beo)?

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?

The slope of a velocity time graph over any interval of time gives the during that interval

What kind of simple machine is a catapult?