Wave Calculation Practice

A pendulum takes 4.0 s to complete one full swing. What is its frequency?

Answer explanation

Frequency is the reciprocal of the period. The period is 4.0 s, so frequency = 1/4.0 s = 0.25 Hz. Thus, the frequency of the pendulum is 0.25 Hz.

A speaker vibrates at 25 Hz. What is its period?

Answer explanation

The period (T) is the reciprocal of frequency (f). T = 1/f. For a speaker vibrating at 25 Hz, T = 1/25 = 0.04 seconds. Thus, the period is 0.04 seconds.

Tags

NGSS.HS-PS4-1

A buoy rises and falls 12 times in 18 s. What is the period?

Answer explanation

a. Frequency is calculated as the number of cycles per second. Here, 12 rises in 18 s gives a frequency of 12/18 = 0.67 Hz. b. The period is the inverse of frequency, so period = 1/frequency = 1/0.67 = 1.5 s.

Tags

NGSS.HS-PS4-1

A strobe light flashes at 50 Hz. What is the time between flashes?

Answer explanation

The frequency of 50 Hz means the strobe light flashes 50 times per second. The time between flashes is the reciprocal of the frequency: 1/50 seconds, which equals 0.02 seconds.

Tags

NGSS.HS-PS4-1

A student taps a desk 15 times in 10 s. What is the frequency?

Answer explanation

Frequency is calculated as the number of events divided by the time period. Here, frequency = 15 taps / 10 s = 1.5 Hz. Thus, the frequency of the taps is 1.5 Hz.

Tags

NGSS.HS-PS4-1

A wave has a period of 0.08 s. What is its frequency?

Answer explanation

Frequency is the inverse of the period. To find frequency (f), use the formula f = 1/T. Here, T = 0.08 s, so f = 1/0.08 = 12.5 Hz. Therefore, the frequency of the wave is 12.5 Hz.

Tags

NGSS.HS-PS4-1

A wave has frequency 6.0 Hz and wavelength 2.5 m. What is its speed?

Answer explanation

To find the speed of a wave, use the formula: speed = frequency × wavelength. Here, speed = 6.0 Hz × 2.5 m = 15.0 m/s. Thus, the wave's speed is 15.0 m/s.

Tags

NGSS.HS-PS4-1

A sound wave has a frequency of 170 Hz and travels at 340 m/s. What is its wavelength?

Answer explanation

To find the wavelength, use the formula: wavelength = speed / frequency. Here, wavelength = 340 m/s / 170 Hz = 2 m. Thus, the wavelength of the sound wave is 2 meters.

Tags

NGSS.HS-PS4-1

A wave on a rope has wavelength 0.40 m and speed 12 m/s. What is its frequency?

Answer explanation

To find the frequency, use the formula: frequency = speed / wavelength. Here, frequency = 12 m/s / 0.40 m = 30 Hz. Thus, the frequency of the wave is 30 Hz.

Tags

NGSS.HS-PS4-1

Water waves pass a dock every 3.0 s and are 9.0 m apart. What is their speed?

Answer explanation

To find the speed of the waves, use the formula: speed = distance/time. The distance between waves is 9.0 m and they pass every 3.0 s. Thus, speed = 9.0 m / 3.0 s = 3.0 m/s.

Tags

NGSS.HS-PS4-1