THis should only take u about less than 5min to do all of them apprently..
if you have time, please help me with this!! paying some fg!!
1.
The speed of sound in air is 343 at 20 degrees C. What is the speed of sound at 100 degrees C? (Hint: Speed is related to the density of air. The density of air is inversely proportional to the temperature IF THE TEMPERATURE IS MEASURED IN KELVINS. To convert between Celcius and Kelvins, add 273, i.e. water freezes at 273 Kelvins).
387 m/s
304 m/s
767 m/s
437 m/s
269 m/s
343 m/s
2.
A boat sitting in the ocean explodes. Person A is surfing 500 m north of the explosion. Person B is deep-sea-diving 1 km below the explosion (wearing futuristic wet-suit so he is not crushed by the water pressure). In what order do the three people hear the explosion?
A and B at the same time
B, then A
A, then B
3.
A 10 Watts point source emits sound waves radially in all directions. Which statement about the intensity of the sound wave is correct?
The intensity is proportional to 1/r .
The intensity does not depend on the distance "r" from the source.
The intensity is proportional to 1/r2.
The intensity is proportional to r2.
The intensity is proportional to r.
4.
Two trumpet players are playing the same note. If one of them suddenly stops, the sound intensity level decreases by (hint: use equation 15-28)
10 dB
3 dB
2 dB
1 dB
5 dB
6.
A person is standing beside a speaker as it plays a 10,000 Hz tone. The sound waves travel away from the speaker uniformly in all directions. If the distance from the speaker doubles, then the amplitude of the waves that the person observes:
Decreases by a factor of 8
Halves
Decreases by a factor greater than 2 but less than 4
Decreases by a factor of 4
Decreases by less than half
Doesnt change