# Physics - Khan Academy

Projectile motion, mechanics and electricity and magnetism. Solid understanding of algebra and a basic understanding of trigonometry necessary.

## Lessons hide description |
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## 1) Introduction to Vectors and Scalars## Distance, displacement, speed and velocity. Difference between vectors and scalars More free lessons at: http://www.khanacademy.org/video?v=ihNZl |

## 2) Calculating Average Velocity or Speed## Example of calculating speed and velocity More free lessons at: http://www.khanacademy.org/video?v=oRKxm |

## 3) Solving for Time## Simple example of solving for time given distance and rate More free lessons at: http://www.khanacademy.org/video?v=awzOv |

## 4) Displacement from Time and Velocity Example## Worked example of calculating displacement from time and velocity More free lessons at: http://www.khanacademy.org/video?v=lQ-dv |

## 5) Acceleration## Calculating the acceleration of a Porshe More free lessons at: http://www.khanacademy.org/video?v=FOkQs |

## 6) Newton's First Law of Motion## Newton's First Law (Galileo's Law of Inertia). More free lessons at: http://www.khanacademy.org/video?v=CQYEL |

## 7) Newton's Second Law of Motion## Newton's Second Law of Motion: F=ma More free lessons at: http://www.khanacademy.org/video?v=ou9YM |

## 8) Newton's Third Law of Motion## Every action has an equal and opposite reaction More free lessons at: http://www.khanacademy.org/video?v=By-gg |

## 9) Airbus A380 Take-off Time## Figuring how long it takes an a380 to take off given a constant acceleration More free lessons at: http://www.khanacademy.org/video?v=p4DTo |

## 10) Airbus A380 Take-off Distance## How long of a runway does as a380 need More free lessons at: http://www.khanacademy.org/video?v=fQt69 |

## 11) Why Distance is Area under Velocity-Time Line## Understanding why distance is area under velocity-time line More free lessons at: http://www.khanacademy.org/video?v=d-_eq |

## 12) Average Velocity for Constant Acceleration## Calculating average velocity when acceleration is constant More free lessons at: http://www.khanacademy.org/video?v=MAS6m |

## 13) Acceleration of Aircraft Carrier Takeoff## Using what we know about takeoff velocity and runway length to determine acceleration More free lessons at: http://www.khanacademy.org/video?v=VYgSX |

## 14) Race Cars with Constant Speed Around Curve## When acceleration could involve a change in direction and not speed More free lessons at: http://www.khanacademy.org/video?v=ITA1r |

## 15) Introduction to Gravity## Basics of gravity and the Law of Universal Gravitation More free lessons at: http://www.khanacademy.org/video?v=Xcel4 |

## 16) Mass and Weight Clarification## Difference between mass and weight More free lessons at: http://www.khanacademy.org/video?v=IuBoe |

## 17) Gravity for Astronauts in Orbit## Why do astronauts appear weightless despite being near the Earth? More free lessons at: http://www.khanacademy.org/video?v=oIZV- |

## 18) Would a Brick or Feather Fall Faster## What would fall faster on the moon? More free lessons at: http://www.khanacademy.org/video?v=36Rym |

## 19) Deriving Displacement as a Function of Time, Acceleration and Initial Velocity## Deriving displacement as a function of time, constant acceleration and initial velocity More free lessons at: http://www.khanacademy.org/video?v=wlB0x |

## 20) Plotting Projectile Displacement, Acceleration, and Velocity## Plotting projectile displacement, acceleration, and velocity as a function to change in time More free lessons at: http://www.khanacademy.org/video?v=T0zpF |

## 21) Projectile Height Given Time## Figuring out how high a ball gets given how long it spends in the air More free lessons at: http://www.khanacademy.org/video?v=IYS4B |

## 22) Deriving Max Projectile Displacement Given Time## Deriving a formula for maximum projectile displacement as a function of elapsed time More free lessons at: http://www.khanacademy.org/video?v=P7LKE |

## 23) Impact Velocity From Given Height## Determining how fast something will be traveling upon impact when it is released from a given height More free lessons at: http://www.khanacademy.org/video?v=2ZgBJ |

## 24) Visualizing Vectors in 2 Dimensions## Visualizing, adding and breaking down vectors in 2 dimensions More free lessons at: http://www.khanacademy.org/video?v=xp6ib |

## 25) Projectile at an Angle## Figuring out the horizontal displacement for a projectile launched at an angle More free lessons at: http://www.khanacademy.org/video?v=ZZ39o |

## 26) Different Way to Determine Time in Air## Another way to determine time in the air given an initial vertical velocity More free lessons at: http://www.khanacademy.org/video?v=_NWc3 |

## 27) Launching and Landing on Different Elevations## More complicated example involving launching and landing at different elevations More free lessons at: http://www.khanacademy.org/video?v=a5QnX |

## 28) Total Displacement for Projectile## Reconstructing the total displacement vector for a projectile More free lessons at: http://www.khanacademy.org/video?v=UXORC |

## 29) Total Final Velocity for Projectile## Calculating the total final velocity for a projectile landing at a different altitude (mistake near end: I write 29.03 when it should be 26.03 m/s and the final total magnitude should be 26.55 m/s 78. ... |

## 30) Correction to Total Final Velocity for Projectile## Correction to "Total Final Velocity for Projectile" Video More free lessons at: http://www.khanacademy.org/video?v=DNoDJ |

## 31) Projectile on an Incline## Challenging problem of a projectile on an inclined plane More free lessons at: http://www.khanacademy.org/video?v=jNESn |

## 32) Unit Vectors and Engineering Notation## Using unit vectors to represent the components of a vector More free lessons at: http://www.khanacademy.org/video?v=2Qjdc |

## 34) Optimal angle for a projectile part 2 - Hangtime## Optimal angle for a projectile part 2 - Hangtime More free lessons at: http://www.khanacademy.org/video?v=XtAB9 |

## 35) Optimal angle for a projectile part 3 - Horizontal distance as a function of angle (and speed)## Horizontal distance as a function of angle (and speed) More free lessons at: http://www.khanacademy.org/video?v=-h_x8 |

## 37) Normal Force and Contact Force## The force that keeps a block of ice from falling towards the center of the earth More free lessons at: http://www.khanacademy.org/video?v=1WOrg |

## 38) Normal Force in an Elevator## How the normal force changes when an elevator accelerates More free lessons at: http://www.khanacademy.org/video?v=hoRsH |

## 39) Inclined Plane Force Components## Figuring out the components of the force due to gravity that are parallel and perpendicular to the surface of an inclined plane More free lessons at: http://www.khanacademy.org/video?v=TC23w |

## 40) Ice Accelerating Down an Incline## Figuring out the acceleration of ice down a plane made of ice More free lessons at: http://www.khanacademy.org/video?v=Mz2nD |

## 41) Force of Friction Keeping the Block Stationary## Block of wood kept stationary by the force of friction (Correction made in next video) More free lessons at: http://www.khanacademy.org/video?v=v8ODI |

## 42) Correction to Force of Friction Keeping the Block Stationary## Correction to Force of Friction Keeping the Block Stationary More free lessons at: http://www.khanacademy.org/video?v=BukTc |

## 43) Force of Friction Keeping Velocity Constant## Calculating the coefficient of kinetic friction (correction made in next video) More free lessons at: http://www.khanacademy.org/video?v=iA7Th |

## 44) Intuition on Static and Kinetic Friction Comparisons## Why static friction is harder to overcome than kinetic friction More free lessons at: http://www.khanacademy.org/video?v=J9BWN |

## 45) Static and Kinetic Friction Example## Thinking about the coefficients of static and kinetic friction More free lessons at: http://www.khanacademy.org/video?v=ZA_D4 |

## 46) Introduction to Tension## An introduction to tension. Solving for the tension(s) in a set of wires when a weight is hanging from them. More free lessons at: http://www.khanacademy.org/video?v=_UrfH |

## 47) Tension (part 2)## A slightly more difficult tension problem. More free lessons at: http://www.khanacademy.org/video?v=zwDJ1 |

## 48) Tension in an accelerating system and pie in the face## The second part to the complicated problem. We figure out the tension in the wire connecting the two masses. Then we figure our how much we need to accelerate a pie for it to safely reach a man's f ... |

## 49) Introduction to Momentum## What momentum is. A simple problem involving momentum. More free lessons at: http://www.khanacademy.org/video?v=XFhnt |

## 50) Momentum: Ice skater throws a ball## A simple conservation of momentum problem involving an ice skater and a ball More free lessons at: http://www.khanacademy.org/video?v=vPkkC |

## 51) 2-dimensional momentum problem## An example of conservation of momentum in two dimensions. More free lessons at: http://www.khanacademy.org/video?v=CFygK |

## 52) 2-dimensional momentum problem (part 2)## We finish the 2-dimensional momentum problem More free lessons at: http://www.khanacademy.org/video?v=leudx |

## 53) Introduction to work and energy## Introduction to work and energy More free lessons at: http://www.khanacademy.org/video?v=2WS1s |

## 54) Work and Energy (part 2)## More on work. Introduction to Kinetic and Potential Energies. More free lessons at: http://www.khanacademy.org/video?v=3mier |

## 55) Conservation of Energy## Using the law of conservation of energy to see how potential energy is converted into kinetic energy More free lessons at: http://www.khanacademy.org/video?v=kw_4L |

## 56) Work/Energy problem with Friction## A conservation of energy problem where all of the energy is not conserved. More free lessons at: http://www.khanacademy.org/video?v=YvacY |

## 57) Introduction to mechanical advantage## Introduction to simple machines, mechanical advantage and moments. More free lessons at: http://www.khanacademy.org/video?v=pfzJ- |

## 58) Mechanical Advantage (part 2)## More on mechanical advantage, levers and moments. More free lessons at: http://www.khanacademy.org/video?v=DiBXx |

## 59) Mechanical Advantage (part 3)## Introduction to pulleys and wedges More free lessons at: http://www.khanacademy.org/video?v=vSsK7 |

## 60) Center of Mass## Introduction to the center of mass More free lessons at: http://www.khanacademy.org/video?v=VrflZ |

## 61) Introduction to Torque## An introduction to torque More free lessons at: http://www.khanacademy.org/video?v=QhuJn |

## 62) Moments## Introduction to moments More free lessons at: http://www.khanacademy.org/video?v=ESusD |

## 63) Moments (part 2)## 2 more moment problems. More free lessons at: http://www.khanacademy.org/video?v=peXbz |

## 64) Unit Vector Notation## Expressing a vector as the scaled sum of unit vectors More free lessons at: http://www.khanacademy.org/video?v=FaF3v |

## 65) Unit Vector Notation (part 2)## More on unit vector notation. Showing that adding the x and y components of two vectors is equivalent to adding the vectors visually using the head-to-tail method More free lessons at: http://www.kh ... |

## 66) Projectile Motion with Ordered Set Notation## Solving the second part to the projectile motion problem (with wind gust) using ordered set vector notation More free lessons at: http://www.khanacademy.org/video?v=jl_gQ |

## 67) Centripetal Force and Acceleration Intuition## The direction of the force in cases of circular motion at constant speeds More free lessons at: http://www.khanacademy.org/video?v=vZOk8 |

## 68) Visual Understanding of Centripetal Acceleration Formula## Visual understanding of how centripetal acceleration relates to velocity and radius More free lessons at: http://www.khanacademy.org/video?v=NH1_s |

## 69) Relationship between angular velocity and speed## How angular velocity relates to speed More free lessons at: http://www.khanacademy.org/video?v=zAx61 |

## 70) Calculus proof of centripetal acceleration formula## Proving that a = v^2/r More free lessons at: http://www.khanacademy.org/video?v=XjCEu |

## 71) Loop De Loop Question## Asks students to find the minimum speed necessary to complete the loop de loop More free lessons at: http://www.khanacademy.org/video?v=wjZb3 |

## 72) Loop De Loop Answer part 1## Figuring out the minimum speed at the top of the loop de loop to stay on the track More free lessons at: http://www.khanacademy.org/video?v=4SQDy |

## 73) Loop De Loop Answer part 2## Figuring out the car's average speed while completing the loop de loop More free lessons at: http://www.khanacademy.org/video?v=zcnnZ |

## 74) Acceleration Due to Gravity at the Space Station## What is the acceleration due to gravity at the space station More free lessons at: http://www.khanacademy.org/video?v=R5CRZ |

## 75) Space Station Speed in Orbit## Speed necessary for the space station to stay in orbit More free lessons at: http://www.khanacademy.org/video?v=9BNkm |

## 76) Conservation of angular momemtum## Angular momentum is constant when there is no net torque. More free lessons at: http://www.khanacademy.org/video?v=s_R8d |

## 77) Introduction to Newton's Law of Gravitation## A little bit on gravity More free lessons at: http://www.khanacademy.org/video?v=391tx |

## 78) Gravitation (part 2)## A little bit more on gravity More free lessons at: http://www.khanacademy.org/video?v=8i0j3 |

## 79) Intro to springs and Hooke's Law## Introduction to Hooke's Law More free lessons at: http://www.khanacademy.org/video?v=ZzwuH |

## 80) Potential energy stored in a spring## Work needed to compress a spring is the same thing as the potential energy stored in the compressed spring. More free lessons at: http://www.khanacademy.org/video?v=eVl5z |

## 81) Spring potential energy example (mistake in math)## A spring, a frozen loop-d-loop and more! (See if you can find the mistake I made and get the right answer!) More free lessons at: http://www.khanacademy.org/video?v=P3QV9 |

## 82) Introduction to Harmonic Motion## Intuition behind the motion of a mass on a spring (some calculus near the end). More free lessons at: http://www.khanacademy.org/video?v=Nk2q- |

## 83) Harmonic Motion Part 2 (calculus)## We test whether Acos(wt) can describe the motion of the mass on a spring by substituting into the differential equation F=-kx More free lessons at: http://www.khanacademy.org/video?v=xoUpp |

## 84) Harmonic Motion Part 3 (no calculus)## Figuring out the period, frequency, and amplitude of the harmonic motion of a mass attached to a spring. More free lessons at: http://www.khanacademy.org/video?v=oqBHB |

## 85) Fluids (part 1)## What a fluid is. Difference between liquids and gasses (both fluids). More free lessons at: http://www.khanacademy.org/video?v=Pn5YE |

## 86) Fluids (part 2)## Pressure and Pascal's Principal. More free lessons at: http://www.khanacademy.org/video?v=lWDtF |

## 87) Fluids (part 3)## Pressure in a fluid at depth More free lessons at: http://www.khanacademy.org/video?v=5EWjl |

## 88) Fluids (part 4)## Using our understanding of fluid pressure to figure out the height of a column of mercury. More free lessons at: http://www.khanacademy.org/video?v=i6gz9 |

## 89) Fluids (part 5)## Introduction to Archimedes' principle and buoyant force. More free lessons at: http://www.khanacademy.org/video?v=vzID7 |

## 90) Fluids (part 6)## A couple of problems involving Archimedes' principle and buoyant forces. More free lessons at: http://www.khanacademy.org/video?v=wwjtu |

## 91) Fluids (part 7)## Introduction to the study of moving fluids. More free lessons at: http://www.khanacademy.org/video?v=G4CgO |

## 92) Fluids (part 8)## Beginning of the proof of Bernoulli's Equation. More free lessons at: http://www.khanacademy.org/video?v=uqyLO |

## 93) Fluids (part 9)## Second part of the Bernoulli's Equation proof. Beginning of a problem that uses the equation. More free lessons at: http://www.khanacademy.org/video?v=QX2YL |

## 94) Fluids (part 10)## Second part of the example that uses Bernoulli's equation. More free lessons at: http://www.khanacademy.org/video?v=NGpJP |

## 95) Fluids (part 11)## Clarification of the problem in part 10 More free lessons at: http://www.khanacademy.org/video?v=HnfBF |

## 96) Fluids (part 12)## Complete example of a Bernoulli's Equation exercise. More free lessons at: http://www.khanacademy.org/video?v=xlJYY |

## 97) Thermodynamics (part 1)## Intuition of how gases generate pressure in a container and why pressure x volume is proportional to the combined kinetic energy of the molecules in the volume. More free lessons at: http://www.khana ... |

## 98) Thermodynamics (part 2)## Example problem that pv=pv. Introduction to temperature. More free lessons at: http://www.khanacademy.org/video?v=x34OT |

## 99) Thermodynamics (part 3)## Introduction to Kelvin. Example of a problem involving the ideal gas law More free lessons at: http://www.khanacademy.org/video?v=HvYUK |

## 100) Thermodynamics (part 4)## Introduction to the concept of a mole. Universal gas constant R. PV=nRT More free lessons at: http://www.khanacademy.org/video?v=5B1i2 |

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