Menu
CoddyPhysics
START LEARNING
flag En iconEnglishdown icon

Static Friction

Part of the Mechanics section of Coddy's Physics journey. Lesson 13 of 94.

Push gently on a heavy crate and it stays put: static friction pushes back exactly as hard as you push, up to a limit:

fs ≤ μs N

Push harder than μs N and the crate starts to slide.

Graph of friction f against the push F for a 50 kilogram crate: friction rises along with the push up to 196 newtons, then drops to a constant 147 newtons once the crate slides

Static friction matches the push up to its limit, 196 N. Once the crate slides, friction is lower.

challenge icon

Challenge

A 30 kg crate rests on a floor with μ = 0.4 for static friction. Find the smallest push F to the right that starts it sliding.

Try it yourself

quiz iconTest yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Mechanics

1Vectors and Newton's Laws

Right TrianglesWhat is a Vector?Adding VectorsAxes and DirectionsVector ComponentsForces Around UsFriction and TensionNewton's First LawNewton's Second LawNewton's Third LawRecap - Net Force

4Kinematics in 1D

Position and DisplacementVelocityAccelerationMotion GraphsEquations of MotionRecap - Braking Car

7Kinematics and Newton

From Forces to MotionFrom Motion to ForcesTwo-Stage MotionRecap - Elevator

10Springs

Hooke's LawSprings in SeriesSprings in ParallelRecap - Spring Scale

13Momentum in 2D

Momentum as a Vector2D CollisionsExplosionsRecap - Billiards

16Gravitation

Law of GravitationGravity and AltitudeSatellitesKepler's LawsGravitational EnergyEscape VelocitySatellite EnergyRecap - Mission to Orbit

2Friction

What is Friction?Static FrictionKinetic FrictionFriction and Newton's LawsRecap - Sliding Crate

5Vertical Motion

Free FallThrowing UpwardTime in the AirRecap - Dropped Ball

8Project: Delivery Drone

Mission BriefingTakeoff ThrustClimb to AltitudeCruise and BrakePackage Drop

11Elastic Energy

Elastic Potential EnergySpring LaunchersEnergy with SpringsRecap - Spring Launcher

14Circular Motion

Uniform Circular MotionCentripetal AccelerationHorizontal CirclesVertical CirclesLoop the LoopRecap - Car on a Curve

17Final Challenges

Recap - Stunt RampRecap - Crash TestRecap - Space Probe

3Inclined Planes

Forces on an InclineGravity ComponentsFrictionless InclineIncline with FrictionWill It Slide?Recap - Ramp Challenge

6Projectile Motion

Independent AxesHorizontal LaunchLaunch at an AngleRange and Max HeightRecap - Hit the Target

9Work and Energy

WorkKinetic EnergyWork-Energy TheoremGravitational PEConservation of EnergyPowerRecap - Roller Coaster

12Impulse and Momentum

MomentumImpulseConservation of MomentumElastic CollisionsInelastic CollisionsRecap - Air Track

15Simple Harmonic Motion

What is SHM?Mass on a SpringThe PendulumSHM GraphsEnergy in SHMRecap - Oscillator