Mechanics | Relativity Answers

The sound level in a quiet room is 49 dB. Approximately how many times louder is it when a TV is turned on and the sound level is 79 dB? Hint: For every 10 dB the perceived sound level increases by a factor of 2.

A) 4
B) 8
C) 1.6
D) 6

A fish finder uses sonar to find fish under water. It does this by sending out a pulse of sound and measuring the time for the sound to return. If it takes 0.016 s for sound to be detected after being emitted, how far away are the fish? Hint, the speed of sound in water is 1440 m/s.

A person stands at a point 340 m in front of the face of a sheer cliff. If the person shouts, how much time will elapse before an echo is heard?

A) 0.49 s B) 0.99 s C) 340 s

D) 344 s E) 1.98 s

A baseball fan sitting in the cheap seats is 136 m away from homeplate. How much time elapses between the instant that the fan sees a batter hit the ball and the moment the fan hears the crack of the bat?

A geologist is camped 7570 m (4.70 miles) from a volcano that erupts. How much time elapses before the geologist hears the sound from the eruption?

A) 4.70s B) 344s C) 22.0s

D) 0.014s E) 7570s

A trumpet plays a note with a frequency of 537 Hz. At room temperature (25oC) what is the wavelength of this sound?

What is the wavelength of this sound?

One very cold day the temperature was -23oC. What is the wavelength of the sound at this temperature?

The wavelength of a certain sound wave in air is 2.88 m at 20.0 degrees C. What is the wavelength of this sound wave in fresh water, which has a speed of sound of 1482 m/s?

What frequency of sound traveling in air has a wavelength equal to 1.5 m.

A) 344 Hz B) 516 Hz C) 76 Hz

D) 0.004 Hz E) 229 Hz

an electric bulb of 60 W is used for 6 hour per day.calculate the units of energy consumed in one day by the bulb.

A block of mass 2 kg is connected to a freely hanging block of mass 4 kg by a light and inextensible string which passes over pulley at the edge of a table. the 2kg mass is on the surface of the table assumed to be smooth. calculate the acceleration of the system and the tension in the string
options
a) 6.7 m/s2 and 13.3 N
b) 3.3 m/s2 and 34.4 N
c) 0.54 m/s2 and 40.6 N
d) 2.5 m/s 2 and 32.2 N