Which observation about the mid-atlantic ridge region provides the best evidence of the seafloor has been spreading over for millions of years

When a 5.0kg cart undergoes a 2.2m/s increase in speed, what is the impulse of the cart

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?

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?