A student sets up a simple pendulum and finds that the period is 1.7s. To obtain a smaller period he should: a) use heavier bob
b) use lighter bob
c) lengthen the string of pendulum d) shorten the string of pendulum

If an inclined plane is 5 m long and 2 m high, what is its mechanical advantage? a. 2.5 b. 3 c. 7 d. 10

Because air contracts as it cools, the air pressure inside a freezer is typically lower than on the outside. why do ice cubes inside a freezer tend to shrink over time? a. the ice dissolves oxygen from the air, forming a denser crystalline matrix. b. the ice reacts chemically with carbon dioxide in the air, forming gaseous carbon compounds. c. the ice melts, and then the liquid freezes as ice crystals on the bottom of the freezer. d. the ice sublimes, and then the water vapor deposits as ice crystals on the sides of the freezer.

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