DAY 22

#Goals: SWBAT...

1. Interpret the meaning of lines on P-t and V-t graphs.

2. Sketch P-t and V-t graphs which match given characteristics.

Warm-Up (4min)

1. Briefly observe the characteristics of lines A-E. Then copy the graph into your notebook and answer 1-4 below

1. 1. Which object(s) is(are) maintaining a state of motion (i.e., maintaining a constant velocity)?

2. 2. Which object(s) is(are) accelerating? 

3. 3. Which object(s) is(are) not moving?  

4. 4. Which object(s) change(s) its direction?  

CLASSWORK

1. HW Review & Notes on p-t and v-t graphs

• P-t graph

  • slope = rise/run = Δx/Δt = velocity

  • + slope = + v

  • 0 slope = 0 v         (think: "doesn't change". What doesn't change? POSITION, cause it's a position-time graph)

  • - slope = - v

  • - change in slope (curved) = - accel

  • + change in slope (curved) = + accel

• V-t graph

  • slope = rise/run = Δv/Δt = acceleration

  • + constant slope = + constant accel

  • 0 slope = 0 accel    (think: "doesn't change". What doesn't change? VELOCITY, cause it's a velocity-time graph)

  • - constant slope = - constant accel

  • - change in slope (curved) = increasingly - accel

  • + change in slope (curved) = increasingly + accel

2. #022A: Graph Sketching and Recognition (35min)

    - Label your notes with the number and topic listed above

    - You are about to pour through quite a bit of information. It is suggested that you first read the questions and make efforts to answer all the questions.  Physics is learned most effectively when your mind is actively engaged in the processes of analyzing and predicting. Avoid treating the information on this page as factual information to be dumped inside of a mental receptacle. Avoid merely looking at the answers; take the time to study the logic of the answers.

Once you've answered the question, check your answer using the "Show Answer!" link. 

    Link to assignment is HERE. Answer 5-30 in your notes; paraphrase each question in your notes prior to answering. Note that we will do 31-37 Monday, so if you'd like to try those early, go ahead :)

If still unclear, online help is in the links below, or you can Remind message me: 

    LINK for p-t graphs

    LINK for v-t graphs

HOMEWORK

Complete any of the remaining practice problems 5-30 from #010A. Monday you may be required to show your solution to one of these on the board. Be ready! If you have questions, ask via Remind, or bring them to class. 

Labs are due Monday 11:59PM

Acceleration quiz Monday at beginning of class - Review the practice problems from this week. Day 21 has good examples: LINK

Test Revisions

• • Want to retake a portion of the Unit 0 exam? Complete the following, and I will allow you to do a retake next week.

    • Open the exam on schoology, and for each incorrect answer, write,....

      • the problem number

      • your answer

      • the correct answer

      • why you got the problem wrong (what was your misunderstanding). 

#Goals: SWBAT...

1. define inertia

2. explain how object's move when forces are unbalanced and balanced

3. Answer inertia related questions 

Warm-Up (5min) 

Copy and fill in the correct answers for the following:

• 1. Blood rushes from your ______ to your ____ while quickly stopping when riding on a descending elevator.

• 2. To dislodge ketchup from the bottom of a ketchup bottle, it is often turned ______ down and thrusted downward at high speeds and then abruptly ______.

• 3. Headrests are placed in cars to prevent whiplash injuries during _________ collisions.

• 4. While riding a skateboard (or wagon or bicycle), you fly _______ off the board when hitting a curb or rock or other object that abruptly halts the motion of the skateboard.

CLASSWORK

1. #022A: Water Demo of Inertia

• What is in the plates? Do the plates have tall sides?

• We'll have a race, from the sink, to the fire extinguisher, to the projector screen, and back to the sink. If you spill twice, you lose. If you aren't first, you lose.

• GO WIN. 

• Q1: Why is it hard to keep the water in the plate?

• Q2: What physics concept does this illustrate?

2. #022B: Defining Newton's First Law

• Complete the following, and think about the water in the plate:

• An object at rest stays at ____ and an object in motion stays in _____ with the same speed and in the same direction unless acted upon by an _________ force.

• Copy the image from the board. It's a visual showing the same concepts, and we will fill it in together after I do a demo. 

3. #022C: Practice Questions

    LINK Answer 1, 3, 4, 5, 6 (complete outside of class if necessary - I'm here at lunch/nutrition for help)

At Home Learning (HW) 

1. read the following: http://www.physicsclassroom.com/class/newtlaws/Lesson-1/Inertia-and-Mass  While you're reading, think about how mass and balanced/unbalanced forces affect an object's motion, and answer the following:

    a. Who was the first well known scientist to develop the concept of inertia?  

    b. Looking at the images of inclined planes, how do skateboarders and snowboarders use the concept of inertia to their advantage? 

    c. The Olympics are coming, and there's an event which uses these curved "inertial planes" to allow riders to do spectacular aerial tricks. What's the event?

2. #022D:

Inertia & Newton's 1st Law

Take Notes: LINK 1

Watch the video, and answer the EdPuzzle Questions: LINK 2