When the C3 key on a piano keyboard is pressed, a string inside the piano
is struck by a hammer and begins vibrating back and forth at
approximately 130 cycles per second. a. What is the frequency in Hertz of
the sound wave?
__b. Assuming the sound
wave moves with a velocity of 345 m/s, what is the wavelength of the
wave?

Part a)

Frequency of sound is 130 Hz

Part b)

Wavelength of the sound is 2.65 m

Explanation:

Part a)

Frequency of source of the sound is same as the frequency of the sound

Here we know that motion of hammer is back and fourth with frequency

f = 130 cycles per second

so frequency of sound is same as frequency of hammer motion

so we have

Part b)

As we know that the speed of sound is

v = 345 m/s

We know that the frequency of sound is

f = 130 Hz

now the wavelength is given as

so easy. just google the electromagnetic waves and it’ll pop up.