Unit 5 So Far

Multiple Choice

Check-In: How are you doing this week?

• Great!

• Good

• Okay

• Not great

• I could use some help

Unit 5 so far…

Yes, you must answer the
questions to receive credit

Plan for today

1.

Review Unit 5 - Quizizz lesson
a.

We might do these instead of Nearpods, depending on how glitchy/slow
they are

b.

Wave characteristics/properties

c.

Wave behavior

2.

Physics Story Time

​Learning goal: Distinguish between characteristics of a wave and the wave's behavior (reflection & refraction)

So far in Unit 5

Wave characteristics

●Wavelength (𝝺)

●Amplitude

○Crests - highest point

○Trough - lowest point

●Frequency

○Waves per second

○Units of Hertz (Hz)

Match

Match these terms with their descriptions

• frequency

• amplitude

• crest

• trough

• wavelength

waves per second

the distance from the center to a crest or trough

highest point in a wave

lowest point in a wave

the distance in which a wave repeats

• waves per second

• the distance from the center to a crest or trough

• highest point in a wave

• lowest point in a wave

• the distance in which a wave repeats

So far in Unit 5

Calculating wave speed, wavelength or frequency

Equation:

v = 𝝺f

Remember:

𝝺 = v/f

𝝺 = wavelength

f = v/𝝺

f = frequency

V = wave speed or velocity

Multiple Choice

Wave speed depends on which variable(s)?

• wavelength only

• frequency only

• amplitude

• frequency and wavelength

Math Response

$$v\ =\ \lambda f$$

A 500m wave has a frequency of 3 Hz. What is the wave speed?

Type answer here

Correct Answer: 1500

Deg^°

Rad

Math Response

$$\lambda\ =\ \frac{v}{f}$$

A wave from a jet engine has a frequency of 500 Hz. If the speed of the surrounding air is 1500 m/s, what is the wavelength?

Type answer here

Correct Answer: 3

Deg^°

Rad

Math Response

$$f\ =\ \frac{v}{\lambda}$$

The speed of sound is 343 m/s. If a wave has a wavelength of 7m, what is the frequency?

Type answer here

Correct Answer: 49

Deg^°

Rad

New this week: reflection and refraction

Reflection

●Wave bounces when it encounters a
new medium

●Does NOT travel through the medium

●ALL WAVES can reflect

Refraction

●Wave bends when it encounters a new
medium

●DOES travel through the medium, just at
a different angle

●ALL waves can refract, but it’s easier to
see than to hear

​This happens at the boundary between two media

Open Ended

Give an everyday example of reflection.

Open Ended

Give an example of refraction in everyday life.

Poll

Before we move on: what do you think about using Quizizz for lessons?

• I liked Nearpod better

• I like Quizizz better than Nearpod

• I don't really care

• I hate both.

Physics Story Time

Any school-appropriate topic

If you need to ask, it’s probably not appropriate.

Example on the next slide

Must have:

At least 7 sentences

3 examples of reflection (labelled)

3 examples of refraction (labelled)

Physics Story Time Example

George jumps into his time machine, He looks into the cold steel of his time machine and it looked back at him(reflection). He hops in and goes into the great unknown. When he lands, he is back in the park with his greatest enemy. He walks over the lake where his foe stands tall. You can see the terror in the eye of the duck through the water. (reflection) In a moment's notice the duck dashes away in the blink of an eye. Looking over in the pond he could see the fish at an angle.( refraction) He looks to his left and sees a fish hook sitting in the water (refraction) and he get an idea. He grabs the hook and throws it at the duck. It stuck him and George reeled him in. He dragged its body against the water. He could see the life in its eyes leave as it was dragged on the water, (refraction).  George gets back to his time machine. He sees the monster he has become (reflection)