DAY 35
#Goals: SWBAT...
1. set up a lab experiment without being given specific instructions.
2. collect vx data
3. determine delta x correctly
4. get the ball bearing in the cup, 1st time
Warm-Up (5min)
Copy, and fill in the blanks: (now that class is over, I filled in the blanks)
After measuring ytabletop and ycup, I can subtract them, and solve for Δ y .
Using the free-fall equation, I can then solve for the time the projectile takes to fall from that height.
Seperately, I can set up a ramp & displacement zone, then use the time and displacement to find x-velocity (Vx)
Now that I know the flight time and horizontal velocity, I can use that with the velocity equation, vx = Δx/Δt
I'll need to rearrange the velocity equation to solve for displacement, so it looks like...
Δx = vx*Δt
That's the displacement from the edge of the table to where I put the cup on the floor.
Done.
CLASSWORK
1. Ball in the Cup Lab
When you're ready, call me over, I'll bring the cup, and we'll test your skills.
you'll need to video your attempt
I'll video it as well
If you get the ball in the cup, this is your day, and you're a physics master!
If the ball hits to the side of the cup, OOF!, but I'll still give this full credit. Why?
If the ball hits long or short, partial credit
2. #035A: Lab Write-Up, Part #1
Lab #3: Projectile Motion: Ball in a Cup
By Monday, you need the following sections: title, group member names, purpose (it's HERE in the pre-lab), hypothesis (the prompt is on Day 34), materials, procedure (for a procedure example, here's the link to Lab #1, LINK)
Monday we'll discuss your analysis of data and conclusion
Lab write-up will be due Thursday night (aka, parent-teacher conference night of next week
While you collected data as a group, and can consult with group-mates to discuss errors and calculations, your lab write-up is your own work.
Learning at Home (HW)
- Complete 035A
- If you'd like to get a jump start on next week's homework, watch these two videos:
INERTIA
Take Notes: LINK 1
Watch the video, and answer the EdPuzzle Questions: LINK 2
FORCE
Take Notes: LINK 1
Watch the video, and answer the EdPuzzle Questions: LINK 2
- next week (Friday) we will have an exam on motion
- next week (Tuesday) we will have a quiz on projectile motion
No warm-up
035A: EXAM DAY
After the exam, work on homework, or complete the pre-lab (due monday)
035B: Learning at Home (HW):
1. Watch the video to review how to solve free fall problems. Make sure that in your notes, you write down the rearranged equation to solve for free-fall time with an initial velocity of zero. (hint, this shows up about four and a half minutes into the video)
2. Solve the following problem:
Find the time for a horizontally thrown 90 mile/hr ball to hit the ground, if it leaves the throwers hand at 2.00 meters above the ground.
Follow-up question: Does the horizontal speed of the ball affect how long it takes it to fall?
old material below - disregard
#Goals: SWBAT...
1. Describe which friction coefficient refers to moving objects, and which refers to objects at rest
2. Draw accurate FBD's
3. Solve problems involving kinetic and static friction
Warm-Up (5min)
Copy the following, then draw the FBD and list all the given and unknown information.
1. You need to move a 105-kg sofa to a different location in the room. It takes a force of 612 N to start it moving. What is the coefficient of static friction between the sofa and the carpet?
2. Would an applied force of 611N get the sofa moving? What about a force of 611.999N? What about 612.000000001N?
CLASSWORK
1. #035A: An Example of how to solve a Friction Problem, plus some Practice Problems
A. We will solve the warm-up problem together, then you'll solve a few problems on your own
Take notes as we solve
B. Solve these on your own:
Theory Problem:
1. Would the friction between a tire and the road be increased by a wide rather than a narrow tire? Explain.
Math Problems:
2. Mr. Ames is dragging a box full of books from his office to his car. The box and books together have a combined weight of 134 N. If the coefficient of static friction between the pavement and the box is 0.55, how hard must Mr. Ames pull the box in order to start it moving?
3. Suppose that a 52N sled is resting on packed snow. The coefficient of kinetic friction is only 0.12. If a person weighing 650 N sits on the sled, what force is needed to pull the sled across the snow at constant speed?
At Home Learning (HW)
1. Complete the problems from #035A
Want to know more about why the tire question answer is what it is?
http://www.physlink.com/education/askexperts/ae200.cfm
If you're stuck, I'll post some solutions here by the end of the school day
2. #035B: Watch/take notes/complete edPuzzle on the following:
(8:59) Determining the Static Coefficient of Friction between Tires and Snow - EDpuzzle
3. #035C: Work on your problem solving skills by solving this problem. (The video above shows a similar problem, but you'll need to use a different UAM equation to solve this problem.)
4. Derek is playing cards with his friends, and it is his turn to deal. A card has a mass of 2.3 g, and it slides 0.35 m along the table before it stops. If the coefficient of kinetic friction between the card and the table is 0.24, what was the initial speed of the card as it left Derek’s hand?