Correction of definition of "normal force" and an introduction to the coefficient of friction. This video, which is suitable for high school students, starts with a black screen because the instructor, in his conversational tone, uses it as a 'chalkb...oard.' (09:25)[more]

Calculating the acceleration of on object sliding down an inclined plane with friction. This ten-minute video, which is suitable for high school students, starts with a black screen because the instructor, in his conversational tone, uses it as a 'ch...alkboard.'[more]

Fun with two masses, some wire, a pulley, and a ramp with friction. This video, which is suitable for high school students, starts with a black screen because the instructor, in his conversational tone, uses it as a 'chalkboard.' (10:15)

Determine if the book moves or not and the acceleration of the book. It’s all about static and kinetic friction.
Want Lecture Notes? This is an AP Physics 1 topic.
Content Times:
0:08 Reading and translating the problem
0:57 5 Steps to help solv...e any Free Body Diagram problem
1:26 Drawing the Free Body Diagram
2:24 Sum the forces in the y-direction
3:22 Sum the forces in the x-direction
4:56 The answer to part (a)
6:22 Solving part (b)
Next Video: Everybody Brought Mass to the Party!
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Previous Video: Experimentally Graphing the Force of Friction
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This is how you include air resistance in projectile motion. It requires the Drag Force and Numerical Modeling (or the Euler Method). It is also very helpful to use a spreadsheet to do the calculations. I prove a statement from a previous projecti...le motion problem video, "Air resistance decreases the x displacement of the ball by less than 1 cm."
Content Times:
0:22 The statement this video proves
1:01 The basic concept of air resistance
1:54 The Free Body Diagram
2:20 The Drag Force Equation
3:13 Information about the Lacrosse Ball
4:03 The Drag Coefficient
4:55 The Density of Air
5:18 How the Drag Force affects the motion
5:58 The basic idea of Numerical Modeling (or the Euler Method)
6:50 Solving for the acceleration in the x direction
8:53 Solving for the final velocity in the x direction
9:54 Solving for the final position in the x direction
11:41 Entering the Lacrosse Ball information into Excel
13:34 Solving for the Drag Force in x direction in Excel
14:29 Solving for the acceleration in the x direction in Excel
14:58 Solving for the final velocity and final position in the x direction in Excel
15:46 Solving for the acceleration in the y direction
17:21 Solving for all the variables in the y direction in Excel
19:13 Click and Drag Copy. Harnessing the Power of Excel!
19:43 Understanding the numbers in Excel
20:35 Solving for the decrease in the x displacement caused by the Drag Force
Want lecture notes & the Excel File?
The original problem videos for this are:
(part 1 of 2) An Introductory Projectile Motion Problem with an Initial Horizontal Velocity
(part 2 of 2) An Introductory Projectile Motion Problem with an Initial Horizontal Velocity
How Many Attempts did it Really Take? - with live music from Amos Lee
Next Problem: Nerd-A-Pult – An Introductory Projectile Motion Problem
1¢/minute[more]

To help understand the force of friction, mr.p pulls on a wooden block using a force sensor. Want Lecture Notes?
This is an AP Physics 1 topic.
Content Times:
0:17 Drawing the Free Body Diagram
0:43 Summing the forces in the x-direction
1:21 Gr...aph when the block doesn’t move
1:46 Graph with the block moving
Next Video: Does the Book Move? An Introductory Friction Problem
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Previous Video: Understanding the Force of Friction Equation
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Bobby teaches the basics of friction and the differences between Static and Kinetic Friction. Want Lecture Notes?
This is an AP Physics 1 topic.
Content Times:
0:11 Basic definition of friction
0:40 What causes friction?
1:30 Static and kinetic... friction demonstrated
2:10 Friction is independent of surface area
2:47 The direction of the force of friction
Multilingual? Please help translate Flipping Physics videos!
Next Video: Introduction to the Coefficient of Friction
Previous Video: An Introductory Tension Force Problem
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The Force of Friction Equation is actually three equations is one. Learn why! Want Lecture Notes? This is an AP Physics 1 topic.
Content Times:
0:00 The basic Force of Friction Equation
0:20 One Kinetic Friction Equation
0:39 The Two Static Fric...tion Equations
1:40 Example Free Body Diagram
2:16 The direction of the Force of Friction
3:20 Determining the magnitude of the Force of Static Friction
4:09 Understanding the “less than or equal” sign
6:08 If the “less than or equal” sign were not there
Next Video: Experimentally Graphing the Force of Friction
Multilingual? Please help translate Flipping Physics videos!
Previous Video: Introduction to the Coefficient of Friction
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We use Newton’s Second Law and Uniformly Accelerated Motion to experimentally determine the Static Coefficient of Friction between Tires and Snow. Want Lecture Notes?
This is an AP Physics 1 topic.
Content Times:
0:09 Reading and translating the ...problem
1:03 Visualizing the experiment
1:16 Where to begin?
1:45 Drawing the Free Body Diagram
3:09 Summing the forces in the y-direction
4:47 Summing the forest in the x-direction
6:24 Uniformly Accelerated Motion
7:35 Solving for the coefficient of static friction
8:18 All 9 trials
Next Video: Breaking the Force of Gravity into its Components on an Incline
Multilingual? Please help translate Flipping Physics videos!
Previous Video: Everybody Brought Mass to the Party!
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