The Period, or the time it takes for wave to complete on wavelength, is related to ____________Frequency

A wave has a frequency of 40 hertz. What is the period of the wave?

• Know:• Find:• Formula:•

Answer:

f = 40hertzPeriod

T = 1/ f

T = 1/f = 1/40 = 0.025s

A wave has a period of 2 seconds. What is the frequency of the wave?

• Know:• Find:• Formula:•

Answer:

T = 2sfrequency

f = 1/ T

f= 1/T = 1/2 = 0.5Hz

The only thing that affect wave speed is the medium

We can use two properties of a wave to calculate the speed:

Frequency- (how many waves per second)Wave Length- (distance between waves)

Finding Speed of a Wave

The wavelength for a wave is 0.5 meter, and its frequency is 40 hertz. What is the speed of the wave?

• Know:• Find:• Formula:•

Answer:

f = 40hertz ƛ = 0.5mSpeed

v = fƛ

v = 40hrtz x 0.5m = 20m/s

The period of a wave is 10 seconds and the wavelength is 2 meters. What is the wave speed?

• Know:• Find:• Formula:•

Answer:

T = 10s ƛ = 2mWave Speed

v = f ƛ

v = f ƛ =

f = 1/T = 1/10 = 0.1hz

v = 0.1hrtz x 2m = 0.2m/s

Can rearrange formula to solve for either frequency or wavelength

A sound wave has a speed of 400m/sec and a frequency of 200Hz. What is its wavelength?

• Know:• Find:• Formula:•

Answer:

v = 400m/s f= 200HzWavelength

v =fƛ

v/f = fƛ / f

ƛ = v/f = 400/200 =2m

Summarizer: Try these on your own!

Johnny is making waves on a slinky. It takes 0.5s for one complete wavelength. The wavelength of the waves is 2m. What is the speed of the waves John-boy made?

• Johnny now creates waves with a speed of 3m/s, with a wavelength of 0.25m.

What is the frequency of the waves?

What is the period of the waves?