Air pressure is
gravity's pull on air molecules
higher the farther you are from earth's surface
about 5 lbs per square inch at sea level
difficult to measure

When the velocity of an object is doubled, by what factor is its momentum changed? by what factor is its kinetic energy changed? a) the momentum is zero. b) the momentum is not zero. c) difficult to say.

The roller coaster from problem #1 then tops a second hill at 15.0 m/s, how high is the second hill? 91.5 m 79.2 m 80.0 m 68.5 m

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