Optics B/C

[Froggie]

Hi all,

I'm in a really desperate situation right now. Because of today's snowstorm (in NJ), school has been cancelled for today. The weather forecast for my town says that the high temperature for tomorrow is 13 degrees and the low is 2 degrees; however, it will be a sunny day. Hence, the sun will melt the snow but then it will freeze and turn into ice. Therefore, school might be cancelled tomorrow (again).

With that being said, I left my Optics LSS at school yesterday; if there is no school tomorrow, I will not be able to retrieve my LSS and do some much-needed practice for Optics. Even worse, I have regionals (at UCC) next Tuesday; furthermore, I haven't even finished making my templates! What do I do???!!!

This is probably a long shot but you could make a paper version of this and finish your template on that.

[Adi1008]

What happens if the image goes past the second lens and is inverted?

First ray: Back project from the first image through the center of the second lens for one ray (since this ray is undeflected by the second lens).
Second ray: Go from the original object through the first focus, and then the first lens which then emerges parallel to the principal axis. Then, it'll go through the second lens and go towards the second focus.

The intersection of these two ray should help you define the final image.

I think it shouldn't matter much whether the image from the first lens inverted or upright

Can you explain this one?
"Two thin converging lenses each with a focal length of 40 cm are positioned with 40 cm apart. An object is placed 60cm to the left of the first lens."

Sure.

For the first lens:


Because the lenses are separated by 40 centimeters, the location of the object for the second lens is -80 centimeters. Therefore:


Sorry for the late response!

[Alex-RCHS]

From the practice tests that you guys have taken, which ones would you most recommend?

[lbeals]

As I read the event description, I do not see that EMR spectrum, the nature of light, red/blue shift, and photon calculations are part of it. Is this a quality control issue with the tests being written for invitationals, or are the events not expected to follow their descriptions more strictly? Should I be reading between the lines to broaden what I cover as a coach?

[WhatScience?]

As I read the event description, I do not see that EMR spectrum, the nature of light, red/blue shift, and photon calculations are part of it. Is this a quality control issue with the tests being written for invitationals, or are the events not expected to follow their descriptions more strictly? Should I be reading between the lines to broaden what I cover as a coach?

A typical test will have what is covered with the rules and then it will go further.

If I were you, I would teach your students what's on the list AND teach them Optics out of a couple of textbooks, covering what they don't already know.

[ElPotato]

As I read the event description, I do not see that EMR spectrum, the nature of light, red/blue shift, and photon calculations are part of it. Is this a quality control issue with the tests being written for invitationals, or are the events not expected to follow their descriptions more strictly? Should I be reading between the lines to broaden what I cover as a coach?

While those topics aren't in the rules, not all invitational tests follow the rules, most likely due to the quality control issue that you mentioned. If these topics keep appearing on tests, it would probably be advantageous to have your team learn them. I can say from personal experience that the EMR spectrum and the nature of light are frequently tested subjects, even though the rules do not specifically include them in the scope.

[Pizzacats]

Are we allowed to leave the template that we made in the box, when the proctors are testing it?

[John Richardsim]

Are we allowed to leave the template that we made in the box, when the proctors are testing it?

Yes (see last sentence of 4.m. in the rules).

[MattChina]

Is there a formula or strategy for LSS (Division B). First time here doing any middle school event

you could also use a protractor with a string tied to it.

[terence.tan]

do you guys use any templates for the laser shoot