DAY 33

#Goals: SWBAT...

1. solve two dimension free-fall problems

2. choose the correct equations for the placement of the cup

Warm-Up (5min) 

1. What is a "plumb bob"? (look it up if you need to)

2. In which field of work is a plumb bob used?

3. do you have anything in your possession that can function as a plumb bob?

4. Does a projectile falling straight down fall faster, slower, or at the same speed as a ball falling with horizontal velocity? Watch the video to see the answer, then use what you saw to think about how to find the time the projectile takes to hit the ground

   • Check this video to see the answer: https://www.youtube.com/watch?v=PuhxNivCKOA

CLASSWORK

1. #033A: Practice Problems 

    Try the following: A pool ball leaves a 0.60-meter high table with an initial horizontal velocity of 2.4 m/s. Predict the time required for the pool ball to fall to the ground and the horizontal distance between the table's edge and the ball's landing location.

    - find given, unknown, equation in both x and y directions

    - solve

    Solve another: A soccer ball is kicked horizontally off a 22.0-meter high hill and lands a distance of 35.0 meters from the edge of the hill. Determine the initial horizontal velocity of the soccer ball.

    - want to check your work? go here: LINK , scroll almost to the bottom of the page to "Check Your Understanding" and click the "check answer" button. 

2. #033B: Pre-Lab completion 

• Work in your groups. Each person must write their answers on their own documnet, which will be your "ticket" to begin the lab Thursday. Check the info below, and use today/Wednesday to make any revisions. If your pre-lab isn't complete and correct, you'll have to finish it instead of working on the lab with your groupmates.... 

• You need to come up with a procedure for this lab. One way to come up with a procedure is to "work backwards"

  • With that in mind, the last thing you'll do is put the cup a certain distance from the end of the table. How will you know where to put the cup?

  • HINT: The answer to the above has something to do with the time the projectile is in the air, its horizontal velocity, and solving the math problems we did in class today. 

  • With that in mind, "How will you measure vx?" And how can you calculate the time the projectile is in the air?

  • HINT: Respectively, the answers to the above have something to do distance and time, and with free-fall

• Some things to consider today while you're answering the pre-lab questions:

  • Consider your answer to Pre-lab #1 and answer this question: Which path will your rolling projectile take when it leaves the edge of the table? (see pic on board)

  • To think about how to measure vx, consider the following. Ignoring friction, where can we assume the marble has constant velocity (there are two correct answers). Of those two places, which would be easiest to measure vx? Choose two of the following three options:

    • on ramp

    • on horizontal table

    • in air (free-fall)

  • In case you missed it in the warm-up, this is important: Does a projectile falling straight down fall faster, slower, or at the same speed as a ball falling with horizontal velocity? Watch the video to see the answer, then use what you saw to think about how to find the time the projectile takes to hit the ground

    • Check this video to see the answer: https://www.youtube.com/watch?v=PuhxNivCKOA

  • Still struggling with Pre-Lab questions #2-5? The HW video on projectile motion covers the same type of problem. Follow Mr. P through the solution for the times listed below

    • 4:29 Beginning to solve the problem.

    • 5:13 Solving for the change in time in the y-direction.

    • 6:22 Solving for the displacement in the x-direction.

    • 7:29 Video proof that it works.

    • Video LINK

On Thursday, we'll do the following:

set up a lab experiment without being given specific instructions. 

1. #034A: Lab 3: Projectile Motion: Setup & Data Collection 

• Have Mr. Alexander check your experimental setup

• Begin collecting data

2. #034B: Lab Data Collection  - Sample Procedure

This is one set of steps you can use to successfully complete the lab. 

• Make a data table with displacement and time. On your table, mark your xi and xf points with small pieces of tape - I suggest that your displacement length should be .20m - .30m, but it's up to you. You must collect constant velocity data on a FLAT SURFACE. Collect 10 trials for the time. Take the average of those ten time values to find your average time.

• Use the time and displacement to find vx.

• Measure delta y between the top of the cup and the table top (you can measure the ycup, ytabletop, and _________ the two. 

• solve the free-fall problem to determine the time to fall delta y

• Use the free-fall time and the vx you calculated to calculate delta x for your projectile motion

• Use a plumb bob to find the initial x position for your projectile motion

• measure out the location for your cup.

• When you're ready, call me over for your one attempt, and put your cup in the correct spot. Video your attempt.

At Home Learning (HW) 

1. Complete the two practice problems from 33A

2. Finish your Pre-Lab from yesterday. If you need me to unsubmit it, just message me on the Remind App.

3. Questions? Send a message. I'll be available Wednesday.

#033B: Continue reviewing notes and practice problems (from the videos and your notes) for Friday's Exam

You can make a one page sheet of equations for the exam

Exam topics: 

1. significant figures

2. conversion factors

3. Speed, Velocity, Distance, Displacement, Scalars, Vectors problems and problem solving

4. Acceleration problems with a zero and non-zero initial velocity

5. Free-Fall

6. p-t and v-t graphs

#Goals: SWBAT...

1. Match activities with one of Newton's Three Laws

2. Recall Newton's Three Laws from memory

3. Determine which forces are present in a variety of scenarios

Warm-Up (6min) 

Copy the following:

• Which of the three laws am I demonstrating?

• 1. tossing the cap: 

• 2. applying force to two boxes:

• 3. sitting in chair: 

CLASSWORK

1. #033A: Newton's Laws Quiz

2. #033B: Forces/Newton's Laws Post-Assessment

LINK Complete all the post-assessment, as well as 7-11 from the last two pages in the link

3. #033C: Quiz Grading

At Home Learning (HW) 

1. LINK Complete all the post-assessment, as well as 7-11 from the last two pages in the link

2. TBD: There will be a video here...