Mechanics | Relativity Answers

An apple falls from a tree and hits the ground
9.41 m below.
With what speed will it hit the ground?
The acceleration of gravity is 9.8 m/s
2
.
Answer in units of m/s

Huong left the white house and traveled east. 0.3 hours later Shanice left traveling at 64 mph in an effort to catch up to Huong. After traveling for 0.7 hours Shanice finally caught up. What was Huong's average speed?

A listener moves toward a stationary source emitting a frequency of 260 Hz at a speed of 52 m/s. What is the frequency heard by the listener?

A car honks its horn as it moves away from you. The car is traveling at 30. m/s and the horn has a frequency of 710. Hz. What frequency do you hear? Use 344 m/s for the speed of sound in air.

A) 710 Hz
B) 852 Hz
C) 653 Hz
D) 778 Hz

A car honks its horn as it approaches you. The car is traveling at 16. m/s and the horn has a frequency of 900. Hz. What frequency do you hear?

A) 860 Hz
B) 900 Hz
C) 944 Hz
D) 990 Hz

A musical instrument can be tuned by comparing its frequency to that of a standard such as a tuning fork. Let's say that you hear a beat frequency of 6 Hz when comparing your instrument to a 900-Hz tuning fork. What is the frequency of your instrument?

A) 894 Hz
B) 900 Hz
C) 906 Hz
D) Either 906 Hz or894 Hz but we can't tell which

Now let's say you begin to adjust your instrument's frequency upwards and you
find that the beat frequency goes down. What was the original frequency of your instrument?

A) 900 Hz
B) Still can't tell
C) 906 Hz
D) 894 Hz

A musical instrument can be tuned by comparing its frequency to that of a standard such as a tuning fork. Let's say that you hear a beat frequency of 6 Hz when comparing your instrument to a 900-Hz tuning fork. What is the frequency of your instrument?

A) 894 Hz
B) 900 Hz
C) 906 Hz
D) Either 906 Hz or894 Hz but we can't tell which

Two tuning forks have frequencies of 239 Hz and 246 Hz. If the forks are vibrating at the same time what is the beat frequency?

The sound level of a train is 121 dB when standing at a distance of 11 m. If you moved back to a distance of 22 m, what would be the sound level there?

A) 127 dB
B) 131 dB
C) 115 dB
D) 111 dB

The sound level of a siren is 120 dB. If a second siren is added, what is the new sound level?

A) 130 dB
B) 240 dB
C) 123 dB
D) 126 dB