7. Heather can apply a force of 72N to a wagon in which sits her little brother, Bryce. The combined mass of Bryce and the wagon is 48kg. If starting from
rest, how much speed will the wagon pick up after Heather has pushed the
wagon for 3s?

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?

Which best represents the law of conservation of mass ?

The discovery of the electron as a subatomic particle was a result of