FarleyPhysics.com

Page 19 in your notes.

1. Second law examples.

2. Second Law problems

Return and go over quiz 5

Mythbusters Challenge (page 18 in your notes):

Challenge 1:

Your Challenge today is to test the Mythbuster’s Myth that a car travelling at 142 mph will beat a car falling from 4000 ft. The car is 4000 ft away from the x on the ground and the car is falling from a height of 4000 ft. Calculate what will happen and compare it to what happened in the show. Be sure to convert mph to m/s and ft to meters before doing any calculations.

1. Draw the situation in your notes.

2. Find the time it takes for the car do drop

3. Find the time it takes for the car going 142 to travel 4000 ft.

4. Which one should get to the x first?  By how much?

5. Would the results change if air resistance was taken into account?  How would they change?

Challenge 2 tomorrow.

Page 16: First Law Notes and Interactive Animation.

Definitions:

Force: The push or pull on a mass from a field or from contact.  Measured in Newtons (pounds in the english system).

Inertia: The resistance to a change in motion of an object.

Mass: a measure of the amount of matter (or inertia) in an object.  Measured in kilograms (1000 grams).

First Law: An object in motion stays in motion and and object at rest stays at rest unless acted upon by a force.

Example: Hockey Puck, animation below.

Run this interactive animation.

1. Read the intro, read Newton’s Bio, and go through the three laws.  Take the quiz and write the questions and right answers in your notes. It’s ok to summarize and combine the question and answers.

Homework: Read pages 43-53 in your book and answer 1-9 odd on page 56

1. Go to Applications and find iWork ’09, then open it to find Keynote.  If it asks you to register or any other questions, just click not now or continue to get through all the popups.

2. Choose a theme

3. Double-click the text to change it.  Title your presentation: Time Travel and put you and your partner’s name under the title.

4. Create a new slide by pressing the plus sign.

5. Go to Masters and pick a slide with a picture on it.

6. Make a slide about your your first sentence from your notes.  Don’t include the whole sentence, just what’s important.  Then find an image online that relates to your sentence and drag it onto your slide.

7. Make slides for each of your sentences.  You should end up with 11 total slides.

When you’re done, save it to your desktop with both of your names and then put it in the SLAMA/Class Folders/ Physics5,6,7/Time Travel folder.

Watch Through the Wormhole: Time Travel

1/2 page of notes on interesting things, questions, things you learn, and opinions.

Projectile Motion Simulations 2

For today’s lesson, you will go to the following website:

http://www.physicsclassroom.com/class/vectors/U3L2a.cfm

Answer the following questions based on your reading of the pages and doing the simulations.
1. What is a projectile? Give three examples of projectiles and draw them.
2. What is the only force acting on a projectile?
3. Draw the free body diagram for a projectile.
4. If you knew the mass of a projectile, what would be the force on the projectile? (you wont find this on the site, you need to figure it out yourself)
5. Is force required to keep an object in motion? Which law explains this?
6. Gravity only effects what motion (vertical or horizontal) of a projectile?
7. Draw the path of a projectile with gravity turned off and gravity turned on.
8. Click the “Animation” button on the first page. In the absence of gravity, where should you aim the banana in order to hit the monkey?
9. With gravity turned on, where should you aim the banana? Look at the aiming above the monkey animation and the aiming at the monkey animations at the bottom of the page.
10. If you are going to throw the banana very slow, where should you aim it? What limits how slow you can throw the banana?

There are five animations on THIS PAGE. Answer the following questions while watching them:
11. For the horizontally launched projectile, how does the velocity in the x direction change over time and how does the y velocity change?
12. For the projectile launched at an angle, how does the velocity in the x direction change over time and how does the y velocity change?
13. For the truck driving under a projectile, why does the ball always stay right above the truck? Draw a picture showing this. How do you think air resistance would effect this?
14. For the airplane dropping a package, why does the package always stay under the plane? Draw this. How would air resistance effect what happened?

Page 13 in your notes

Newton’s Laws Computer simulations

Go to this link http://www.beyondbooks.com/psc91/4a.asp

Answer the following questions in your notes.  Be sure to write the questions and answers.

Who influenced Newton the most?
What does Newton’s First Law state?
What is inertia?
Run Galileo’s Experiment and put the marble at 8 meters.  Explain what happens and draw a picture in your notes.
Run Galileo’s Experiment again with the marble at 8 meters and the angle of the opposing plane at zero degrees.  Explain what happens and draw the picture.

Click the Next button news the bottom of the page and answer the following questions:

What is a force?
What is a Contact Force and list four examples.
What is an Action at a distance force and list three examples

Go to this link and try to find the velocity that makes the cannon orbit the earth in a perfect circle.  It will hit the top of the mountain when it comes back around.  Explain what is happening here and include a picture in your notes.

Go to this link and create a 10 N force on a 10 kg cart. Write the equation, the numbers that went into the equation, the answer, and draw the dots that result.

Create a 40 N force on a 10 kg cart. Write the equation, the numbers that went into the equation, the answer, and draw the dots that result.

Create a 10 N force on a 40 kg cart. Write the equation, the numbers that went into the equation, the answer, and draw the dots that result.

Page 11: Projectiles at Zero Degrees

The trick to figuring out how far a projectile will go when it is projected at zero degrees is:

1) Figure out how long it takes for the projectile to drop to the ground.

2) Use the drop time in d=st to find out how far the projectile will go.

Example 1: You shoot a gun at 300 m/s horizontally from a height of 2 meters. How far will the bullet travel before hitting the ground?

Example 2: You kick a rock horizontally off a 30 m high cliff at 5 m/s.  How far from the cliff will the rock hit the ground?

Problems to do in your notebook (Page 12):

For each problem, write the question, do the two steps above, and check your work with the simulation.  Then draw the axes and trajectory from the simulation.

1. You shoot a cannon horizontally from the top of a castle that is 20 m high.  If the cannonball travels at 50 m/s how far will the cannonball travel before reaching the battlefield?

Check your work with this simulation.  Draw the simulation in your notes.

2. You kick a bottle off a 10m high building at a speed of 5 m/s.  How far from the building will the bottle strike the ground?

Check your work with this simulation.  Draw the simulation in your notes.

3. a scared cat slides off a table that is 1 meter high at a speed of 2 m/s.  How far from the table does the cat land?

Check your work with this simulation.  Draw the simulation in your notes.

4. A car drives off a 40 m high cliff at 20 m/s.  How long does the car take to reach the bottom?  How far from the base of the cliff does the car land?

Check your work with this simulation.  Draw the simulation in your notes.

(Page 10)

Today we will use Stomp Rockets to study projectile motion.

1. Find the angle that causes the most hang time.

2.Find the launch angle that launches the furthest.

3. Find the height of 3 launches straight up by measuring the hang time and using 1/2 this in the distance formula.

Projectiles: Straight Up! Notes  (page 8 in your notes)

When a projectile goes straight up, it slows down 10 m/s every second.  The key to finding out how high a projectile will go:

Step 1: first figure out how much time it takes to reach the top of the trajectory.  This is done by dividing its initial speed by 10.

Step 2: Put the time to get to the top into the distance equation for an accelerated object to find out how high the projectile will go.

Example 1: You shoot an arrow with a velocity of 40 m/s straight up.  How high does it rise?  Divide by 10 and you get 4 seconds.  Put it into the equation to find 80 m as the height the arrow will go.

Some other questions you can answer are: How long is the arrow in the air (hang time)?  What speed does it hit the ground with?  What is it’s speed at the top of the trajectory?

Example 2: You throw a ball straight up at 5 m/s.  How high will it rise?

Projectiles: Straight Up Problems.  (Page 9 in your notes)  Write out the entire question.

1. You shoot an arrow straight up at 30 m/s.  How long does it take for the arrow to get to the top of its trajectory? How long is the arrow in the air?  How high does the arrow go?

Test your answers by running this scenario on yesterday’s simulation.  Draw it and write the numbers the simulation creates.

2. You throw a golf ball straight up with a velocity of 10 m/s straight up.  How long does it take the ball to reach the top of the trajectory?  How high does the ball reach?

Test your answers with the simulation, draw it, and write down the numbers the simulation gives you.

3. You shoot a cannonball straight up with a velocity of 110 m/s.  How high will the cannonball go?  Check your answer with the simulation.

4. You shoot a gun straight up and the bullet leaves the barrel at a velocity of 200 m/s.  How high will the bullet go?  How long is the bullet in the air before it hits the ground?  Test your answers with the simulation, draw it, and write down the numbers the simulation gives you.

5. A ball thrown straight up takes 2 seconds to hit the ground.  How high did the ball go?  What speed was the ball thrown at?