Noah decides to test both types of signals during a thunderstorm, when there is a lot of interference. Which signals are more reliable during thunderstorms?

• Analog signals—the larger range of values in these signals means they are more likely to be transmitted successfully through atmospheric noise.
• Digital signals—there are only two values in this type of signal, so atmospheric noise is less likely to cause problems due to interference.
• Neither signal performs better—you can see in the data that noise has affected the wave structure of both signals.

Residents of Blueville have been complaining about the sound traffic coming from the highway. They have hired an engineer who has suggested installing a high wall made of solid concrete along the stretch of highway that runs through town. Which model best explains why the concrete wll will effectively reduce highway noise?

• 
• 
• 
• 

Use the data table. Which materials would be helpful to animals that use echolocation? Select all that apply.

• Hardwood
• Glass
• Foam Insulation
• Metal
• Carpet

Which type of surface would most likely reflect sound waves?

• Soft and Absorbent
• Smooth and Hard
• Rough and Uneven
• Transparent and Thin

The graph below shows information collected during an underwater sonar scan. Based on the data below, if an unknown object had a sound return time of 0.07 seconds, at what depth would it be located?

• 90 m
• 30 m
• 50 m
• 0.1 m

Which model shows how a bat collects information about its prey by making high-frequency sounds?

• A
• B
• C
• D

a signal that varies over time between a pair of different values

• Echolocation

• digital signal

• analog signal

a technique used by some animals to locate the position of objects by producing sounds and listening to their echos

• Echolocation

• digital signal

• analog signal

a continuous signal that varies over time

• Echolocation

• digital signal

• analog signal

Voices can be recorded and transmitted in two ways: 

Analog format: The recording is an exact copy of the information provided. The signals is transmitted as a continuous stream of data. This signals has a huge range of different values. 

Digital format: The recording is made by taking multiple samples of the original sound. The signal transmitted is stepped and discrete. This signal can only have a value of either 1 or 0. 

Question: SIGNAL 1 matches the ___(a)____ voice signal. SIGNAL 2 matches the ____(b)_____

coice signal.

• a- analog

  b- digital

• a- analog

  b-analog

• a- digital

  b- analog

• a- digital

  b- digital