Calculate the wavelengths in air at 20?C for sounds in the maximum range of human hearing. The speed of sound in air is 343 m/s. Part ACalculate the wavelength of a 20-Hz wave. Express your answer to two significant figures and include the appropriate units. Part BCalculate the wavelength of a 20,000-Hz wave. Express your answer to two significant figures and include the appropriate units. Part CWhat is the wavelength of a 20-MHz ultrasonic wave?Express your answer to two significant figures and include the appropriate units.

Part A:  17 m

Part B:  1.7 x 10⁻²m

Part C:  1.7 x 10⁻⁵m

Explanation:

Equation needed to answer the question:

 λ =

where λ is the wavelength, f is the frequency and v is the velocity,

Part A:

Substitute velocity with the speed of sound: 343 m/s

Substitute frequency with the value given: 20 Hz

 λ = = 17 m

Part B:

Substitute velocity with the speed of sound: 343 m/s

Substitute frequency with the value given: 20,000 Hz

 λ = = 1.7 x 10⁻²m

Part C:

Substitute velocity with the speed of sound: 343 m/s

Substitute frequency with the value given: 20,000 Hz

 λ = = 1.7 x 10⁻⁵m

a small object of mass 3.66 g and charge -17.6 µc is suspended motionless above the ground when immersed in a uniform electric field perpendicular to the ground. what are the magnitude and direction of the electric field?