27. Find the acceleration of a particle moving with a con-

stant speed of 8 m/s in a circle 2 m in radius.

An unit for measuring frequency?

How does air resistance affect a gymnast

Which of the following conditions is not necessary to observe an interference pattern between two sets of waves? A) The waves must have the same wavelength. B) The waves must have a constant phase difference.

Seven seconds after a brilliant flash of lightning, thunder shakes the house. approximately how far was the lightning strike from the house?

Lasers can be used in in place of a knife.

Electrons flowing into a resistor make that end A. positive with respect to the other end B. negative with respect to the other end C. higher in resistance D. extremely warm

The force of air resistance acts to oppose the motion of an object moving through the air. A ball is thrown upward and eventually returns to the ground.

The temperature of a substance during an experiment can be modeled by the function f (x) = - 7.5cos (πx30) + 31.4, where f (x) is the temperature °c and x is the number of minutes into the experiment.

Which of the following are good conductors? A. A rubber tire B. A penny C. A newspaper D. An aluminum soda can E. Water F. Air

Ideentify the two atmospheric layers that contain air as warm as 25 degrees Celsius.