14. If a wave hits a smooth surface at an angle of incidence of 40 degrees, the angle of reflection is
A. 0 degrees.
B. 40 degrees.
C. 80 degrees.
D. 90 degrees.
15. When a tuning fork vibrates over an open pipe and the air in the pipe starts to vibrate, the vibrations in the tube are caused by
A. harmonics.
B. reinforcement.
C. beats.
D. resonance.
16. When a sound from a source is refracted away from the surface of the earth, it gives an indication that the
A. air is cooler than the ground.
B. wind is blowing in the direction of the sound.
C. air has high humidity.
D. ground is cooling faster than the air.
2007-02-12 04:26:57 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Physics
14. B. Angle of incidence=angle of reflection.
15. D. Definition of resonance
16. A. Refraction is caused by the bending of waves through different media, or varying media. Sound waves travel slower in cooler air than they do in warmer air. For this reason, the portion of the wave in the higher (cooler air) is slowed down, while the portion of the wave closer to the (warmer) ground speeds ahead. Subsequently, the direction of the wave changes, refracting upwards away from the earth.
2007-02-12 04:56:36 · answer #1 · answered by Capt. Obvious 7 · 0⤊ 1⤋
14. B. They are equal.
15. D.
16. Guessing D.
2007-02-12 04:38:58 · answer #2 · answered by gebobs 6 · 1⤊ 2⤋
14. B
15. D
16. B
2007-02-12 04:47:42 · answer #3 · answered by Virgilio C 2 · 0⤊ 2⤋