Final project

Newtonian Physics

SME 401

Chris Armour

Dominic Held

SME 401

Our final project covers Newtonian physics. We decided to cover this topic for our final project because it is covered in EVERY high school physics class. This is usually the very first topic that is covered in any introductory class. It is the basis for all other physics and we felt it would be beneficial for ourselves as future teachers to investigate this topic since we will eventually one day be teaching it. This lab set is designed for an introductory or AP level high school physics class. The students will know relatively little about physics before we teach this unit. The labs are set up so that as you go through the unit and introduce a new topic in Newtonian physics then there is a lab for that topic. Therefore, these labs are not designed to be used as a unit in themselves, but are designed to be used over the course of a semester or even a year depending on how fast the class is moving and what topics the class talks about. Also, other activities can be used throughout the Newtonian Physics section of the class, but we felt like these were important or especially good labs for the students to perform.

In researching these labs, most of them were labs that we either had while in high school, labs we have seen or have done in college, plus one found online. Most physics labs are universally known to be good and usually these labs are performed throughout most physics classes. Since most of the labs were ones we had experienced at some point, so we knew they were good experiments. Therefore, when we tested the labs to obtain sample data we had no trouble and did not really need to change very much of the labs procedure. The lab we found online was the one on projectile motion. This lab looked like it was high-quality so we decided to test it. Online it was primarily given as a demonstration so I adapted the ideas from the demonstration and applied them to create a 2 day lab for the students. When tested it worked reasonably well at showing projectile motion. This is a hard area in getting good experiments for students to conduct and I think I made a reasonably good experiment with very inexpensive materials. The only lab that might be difficult to recreate exactly in a classroom is the Force of Gravity lab. The apparatus is a little high tech and some classrooms might not be. Fortunately, you can adjust the lab to fit what you do have in the classroom, which is addressed in the teacher materials for that lab.

In assessing the students, since this is not a short unit, and since the topic will be split up into smaller units each with its own exam, each lab will be assessed separately. For the most part the assessments will be done with follow-up questions and worksheets at the end of each lab. The labs will mostly be graded on these questions as well as finished data tables, complete graphs and calculations. The only exception is the mouse trap car lab. This lab will partly be assessed on how far the car goes compared to the rest of the class but will mainly be graded on a follow-up essay the students write. This essay is described further in the student materials for that lab.

Goals and Objectives

·  Introduce the concepts of the semester/year.

·  Spark students’ interest in physics and science in general.

·  Give real experiences of Newton’s three laws.

·  Have students reflect on observations.

·  Incorporate velocity and acceleration into activities to help present their relation.

·  Take measurements of the gravitational force on a mass.

·  Plot data in a graph manually using graph paper and electronically using computer software.

·  Gain experience interpreting graphs.

·  Show how an object’s mass distribution affects angular momentum.

·  Provide an opportunity for students to solve a problem incorporating the concepts of the unit with their creativity.

Activities/Table of Contents:

Pages:

5 – 7 Magic of Physics Demonstration- This demonstration should be given at the beginning of the semester, possibly the first day. Topics that will be discussed throughout the semester will be introduced in an exciting way.

(Time duration 1 day)

8 – 14 Motion Maps: Toy Car Lab- Using a motorized car, students will take measurements and calculate the car’s velocity in this activity. A long room or hallway will be necessary depending on the speed of the car. Students will then use computer software to plot distance vs. time and apply a best fit line to the plot. The slope of this line will equal the velocity of the car.

(Time duration 2 days)

15 – 23 Force of Gravity (Measurement of g) - This activity is done to experimentally find the force of gravity of the earth. By timing how long a ball takes to fall a measured distance we can solve use a kinematic equation to solve for g. The goal of this lab is to show that gravity is caused by the mass of an object (the earth). (Time duration 1 day)

24 – 34 Projectile Motion (Motion in 2-D) - This lab demonstrates projectile motion by looking at how a dart is shot from a dart gun. Different parameters are changed like the angle the dart is shot from, the height above the ground the dart is shot from, and the mass of the dart to investigate how these will affect the horizontal distance the dart flies. (Time duration 2 days)

35 – 43 Rolling Cylinders and Angular Momentum- This activity displays the conversion of potential energy into kinetic energy of motion and kinetic energy of rotation through the use of ramps (inclines), balls and cylinders. It is a good introduction to rotational energy after inclines and pendulums have been discussed.

(Time duration 2 days)

44 – 49 Mouse Trap Car – This activity would be preformed at the end of the whole Newtonian physics unit. The basic premise of this activity is to get the students to use all the knowledge they have gained throughout the unit/semester/year to build a mouse trap car. Not only do they have to build a working car but they need to write a paper that explains all the physics that is involved in their car. This is a good project to wrap up this topic. (Time duration 2 days)

Teacher Materials: Magic of Physics Demonstration

(Time duration 1 day)

Overview:

This demonstration is dependent on the disposition of the presenter. You could really get into character with a cape, hat, and wand, or you could leave the magic part out and just give an interesting demonstration. Either way, you will be demonstrating topics that will be discussed throughout the semester. I chose to leave the depth of the magic show up to the presenter and have just given an outline of possible steps to follow.

Teacher and Student Objectives:

·  Excite students about physics and science.

·  Introduce some of the topics that will be covered throughout the course.

·  Begin thinking about the physics in our everyday lives.

Who’s Being Taught?

This demonstration is designed for an introductory high school physics class consisting of juniors and seniors. The table cloth and bed of cups tricks could be explained to younger students, but the rolling uphill and laser trick require a more experienced audience in order to give an explanation.

Strengths of Exercise:

1.  Visual performance that shows science can be fun.

2.  Introduces the course in an exciting way; who wants to sit through another class reading rules and regulations on the first day of school?

3.  The table cloth trick will lead directly into Newton’s laws.

How to Assess:

After the demonstration, ask for volunteers to explain each trick. Give an explanation to the aspects that the students have trouble explaining in terms of physics.

What to Look Out For:

·  Make sure that all of the demonstrations are setup in areas that will be in view of all of the students.

·  As students enter your classroom, be mindful that they do not disturb the magic tricks.

·  Make sure you have plenty of room when you pull out the table cloth. You do not want to hit a student when you pull it.

·  All tricks should be tested and you should be confident they will work during the demonstration.

·  Be sure to give an explanation of each magic trick.

Technical Information:

Table Cloth Trick: The dishes stay on the table because of Newton’s first law: A body at rest stays at rest unless acted upon by a force. Because the table cloth is so thin and slick, the force on the dishes when the tablecloth is removed is negligible.

Reflected Light Trick: The light is totally reflected by the mirrors, so the angle of incidence to the mirror is equal to the angle of reflection of the light. When the light from the laser is refracted by the grating, the interference pattern is projected on a screen. The interference pattern is caused by constructive and deconstructive interference brought about by the diffraction of the light. Constructive interference happens when wave the crest of waves add and deconstructive interference occurs when wave crests cancel each other out.

Bed of Cups Trick: Pressure is equal to a force divided by an area. The area of a single cup is small so the force on the cup is large. The area of many cups is much larger so the force on the cups is much smaller. P = F/A

Rolling Uphill Trick: The incline of the cones is greater than the incline of the meter sticks. As the meter sticks widen the center of mass of the cones is lower at the top of the slight incline made by the sticks. This is why the cones appear to roll upward.

Materials:

Table Cloth Trick:

·  Heavy dishes with a low center of gravity

·  Thin tablecloth made of slick material (nylon)

·  Large flat surface at the front of the class.

Reflected and Refracted Light Trick:

·  Laser

·  Mirrors

·  Diffraction Grating

Bed of Cups Trick:

·  30 cups

·  2 Trays or sheets of wood

Rolling Uphill Trick:

·  2 Party Hats

·  Tape

·  2 Meter Sticks

·  Books

Procedure:

Table Cloth Trick:

Before Class:

  1. Set up dishes on top of the table cloth.
  2. Make sure there is enough room to pull the table cloth out.

During Class:

  1. Make sure this is no students sitting close behind you.
  2. Say the magic words to keep the dishes on the table.
  3. With one quick motion pull the table cloth down and away.

Reflected Light Trick:

Before Class:

  1. Setup the laser and the mirrors so that the light is reflected from mirror to mirror and finally passing through the diffraction grating onto a screen.
  2. Place something in front of the beam so it is blocked.

During Class:

  1. Inform the class that you are going to create a magical image on the screen.
  2. Wave your wand and say the magic words while nonchalantly knocking aside the object that is blocking the laser beam.

Bed of Cups Trick:

Before Class:

  1. Set up approximately 25 cups in a grid on a tray.
  2. The cups should be pointed down.
  3. Place the tray of cups and empty tray together behind the front desk.
  4. Place 3 or 4 cups on your desk or another easy to reach area.

During Class:

  1. Take a single cup and ask the class what will happen if you step on it.
  2. Take two or three cups and ask the class what will happen if you step on them.
  3. Ask the class how many cups would be needed to hold you up.
  4. Bring out the tray with cups and the empty tray.
  5. Place the tray of cups on the ground and the empty tray on the cups.
  6. Say the magic words and step on the tray.

Rolling Uphill Trick:

Before Class:

  1. Tape together two identical cone shaped party hats.
  2. Build a slight incline with the meter sticks and books.
  3. The meter sticks should be close together at the bottom of the incline and wider at the top.

During Class:

  1. Tell the class that you will make the connected cones roll uphill.
  2. Say the magic words and release the cones at the bottom of the incline.

Follow up:

An introduction to Newton’s laws should follow this demonstration. Be sure to reference the table cloth trick when you talk about Newton’s 1st law. If this demonstration is used on the first day of school, an introduction to the class procedure could be incorporated into the show or given before or after the demonstration.

Resources:

Inspired by Merle Heideman, Fall 2006.


Motion Maps: Toy Car Lab

Introduction:

In this activity you will measure the distance traveled by a motorized car over several intervals of time. As we have discussed in class, velocity is the change in position of object over a period of time, or v = ∆x / s. On the first day you will collect data of your car.

On the second day, you will use the data you collected on the first day to plot distance vs. time using computer software. By finding the slope of the best fit line to your data, you will have calculated the velocity of your car.