Earthquakes and Resonance

Multiple Choice

What type of earthquakes were most common between 2000 and 2012 (the years we examined earlier in class today)?

• Very low magnitude (less than 2)

• Moderate magnitude (2 to 5)

• High magnitude (5-8)

• Extreme magnitude (greater than 8)

Multiple Choice

Which of the labels at left indicates the amplitude of the wave?

• A

• B

• C

• D

• E

Multiple Choice

Which of the labels at left indicates the period of the wave?

• A

• B

• C

• D

• E

Multiple Choice

What is the period of this building's oscillation (back-and-forth movement)?

Hint: It makes 12 back-and-forth motions in 4 seconds.

• 48 seconds

• 6 seconds

• 4 seconds

• 3 seonds

• 0.33 seconds

Multiple Choice

After allowing a pendulum to swing back and forth 10 times, you determine that the period of the pendulum is 2 seconds. What is its frequency?

• 20 Hz

• 10 Hz

• 5 Hz

• 0.5 Hz

• O.2 Hz

Multiple Choice

Very tall buildings have ___ natural frequencies compared to very short buildings.

• smaller

• similar

• larger

Multiple Choice

A skyscraper should be built on

• soft sediment.

• hard bedrock.

• any type of surface.

Multiple Choice

We saw in the lecture today that this is the equation that relates the natural frequency of a building to its length and the acceleration due to gravity. If we make a building 4 times taller than the original, how will this change the natural frequency?

$$f\propto\sqrt[]{\frac{g}{L}}$$

• The taller building will have a natural frequency 4 times greater.

• The taller building will have a natural frequency 2 times greater.

• The taller building will have a natural frequency (1/2) as great.

• The taller building will have a natural frequency (1/4) as great.