Reflection and Transmission of Pulses and Waves

We started off the class with the answers given on the whiteboard from the homework we were assigned to finish the previous day; Describing Waves Assignment #12-16 and page 13 in our handouts #1-2.

Here are the answers you can refer to in case you missed today's class:

Describing Waves
12) D
13) V = λ/T or V = λf
14) 2 m/s
15) 24.2 m
16) 5 s

*For question 16, a few of us got the answer 2 s. I do not think Mr. Vincent heard us ask about it so may you please go over it on Monday?

Page 13
1) 5.2 x 10² m
2) 1.7 x 10^-5 s

We then moved onto Wave Reflections and Wave Transmissions where we experimented with two types of springs; a light medium spring and a heavy medium spring.

We all went in the hallway and watched the reflection pulse of the light medium and heavy medium spring. We learned that when we gave the spring a wave, once the pulse reached the barrier, the rope exerted a force upward on the support. This support then exerted an equal but opposite force downward on the rope. This downward force on the rope is what causes the pulse to reflect back on the opposite side, or inverted. This can be related to Newton's Third Law where; every action has an equal and opposite reaction.

From a free end of a spring, meaning there is no solid barrier at the end, once the pulse reaches the end of the spring, the particles exert an upward pull on the end of the rope which generates a reflected pulse that is now on the same side of the rope as the incoming pulse.

A reflection can be defined as the return of a pulse or wave from the boundary of a medium.

Next was Wave Transmission in Two Media, where we taped together the two different springs. We then tested out what happens to the waves as the two are taped together. We learned that when a wave passes from a fast medium into a slow medium, the particles in the slower medium have greater inertia. The reflected wave is inverted where the transmitted wave is not inverted.

A partial reflection is when a wave moves from one medium to another, some reflection occurs at the boundary between the two media, where some of the energy is transmitted into the new medium and some is reflected back into the original medium.

We then went back to class and drew diagrams of these different types of waves we saw because by the end of this lesson, we should be able to draw transmission and partial reflection of pulses and describe how pulses or waves in one dimension are reflected from a fixed end and a free end. I will attach photos of how the diagrams look like somewhere on this post since I cannot move the image..

There was a remaining 20 minutes of class when we received our next few pages of notes, pages #17-26. These pages should explain everything about the Reflection and Transmission of Pulses and Waves that we learned today.

For homework, we were assigned to finish any questions given in the pages #17-26. This is suppose to help us review for the test we have on Wednesday!

Last but not least, 7evin shall be the scribe for Monday's class. I hope this did not bore any of you..just wanted to cover everything! Have a great weekend.