A police officer parked at the curb turns on his lights and siren, waits for traffic to clear, then pulls out and heads down the street. For an observer down the street, which is true? A. The frequency of the siren is higher and the wavelength is shorter than it was at first.
B. The wavelength of the siren is shorter than it was at first, but the frequency is the same.
C. The wavelength of the siren is shorter and the frequency is lower than it was at first.
D. The frequency of the siren is higher than it was at first, but the wavelength is the same.

The act of moving from one place to another. a. locomotor b. aerobic c. stationary d. static

Aball is thrown upward. at a height of 10 meters above the ground, the ball has a potential energy of 50 joules (with the potential energy equal to zero at ground level) and is moving upward with a kinetic energy of 50 joules. what is the maximum height h reached by the ball? consider air friction to be negligible. 1. h ≈ 10 m 2. h ≈ 50 m 3. h ≈ 30 m 4. h ≈ 40 m 5. h ≈ 20 m 003 10.0 points which of the two object shown below has the greatest kinetic energy? a m b 1 2 m v 2v 1. kinetic energies are the same. 2. a 3. b 4. unable to determine. 004 10.0 points tim, with mass 74.6 kg, climbs a gymnasium rope a distance of 3.1 m. the acceleration of gravity is 9.8 m/s 2 . how much potential energy does tim gain? answer in units of j. 005 10.0 points a car is moving at 64 miles per hour. the kinetic energy of that car is 5 × 105 j. how much energy does the same car have when it moves at 111 miles per hour? answer in units of j. 006 10.0 points an 102 kg man climbs up a 1 m high flight of stairs. the acceleration of gravity is 9.81 m/s 2 . w

The material that keeps its new shape after it is stretched is called?