Question

grade 7_sound waves properties
part 2. describe the oscilloscope. choose the correct answer.
b has greater amplitude
a has greater amplitude
b is louder than a
a is louder than b
a and b have the same frequency
a has more frequency
b has more frequency
b has higher pitch
a has higher pitch
a has more frequency
b has more frequency

Explanation:

Amplitude is the height of the wave from the rest line. Frequency is the number of waves per unit time. Pitch is related to frequency (higher frequency = higher pitch).
For the first set (A and B):

• Looking at amplitude: B has a greater height from the rest line (greater amplitude), so B is louder (since amplitude relates to loudness).
• Looking at frequency: Count the number of waves. A and B have the same number of waves in the given space (same frequency).

For the second set (A and B):

• Looking at frequency: A has more waves in the given space (more frequency), so A has a higher pitch (since pitch is related to frequency).

Answer:

B has greater amplitude, A and B have the same frequency, A is louder than B (no, B is louder as it has greater amplitude - correction), A has more frequency, A has higher pitch.

Wait, re - evaluating:
For the first pair (top A and B):

• Amplitude: B is taller (B has greater amplitude, so B is louder).
• Frequency: Count the number of wave cycles. They are the same (A and B have the same frequency).

For the second pair (bottom A and B):

• Frequency: A has more wave cycles (A has more frequency, so A has higher pitch).

Final Answer:
B has greater amplitude, A and B have the same frequency, B is louder than A, A has more frequency, A has higher pitch.