Acceleration
Part of the Mechanics section of Coddy's Physics journey. Lesson 25 of 94.
Acceleration is the change in velocity divided by the time:
a = (v - v0) / Δt
Unit: m/s². 2 m/s² adds 2 m/s every second.
Each second the velocity grows by 2 m/s, so the car covers more road each second.
A car braking from 20 m/s to 8 m/s in 4 s has a = (8 - 20)/4 = -3 m/s². Velocity and acceleration pointing opposite ways: the object slows down.
Challenge
A skateboarder rolls down a straight hill at 4 m/s and speeds up with a constant acceleration of 3 m/s² for 6 s. Taking downhill as positive, find her final velocity v.
Try it yourself
Test yourselfThis 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 Force4Kinematics in 1D
Position and DisplacementVelocityAccelerationMotion GraphsEquations of MotionRecap - Braking Car2Friction
What is Friction?Static FrictionKinetic FrictionFriction and Newton's LawsRecap - Sliding Crate3Inclined Planes
Forces on an InclineGravity ComponentsFrictionless InclineIncline with FrictionWill It Slide?Recap - Ramp Challenge6Projectile Motion
Independent AxesHorizontal LaunchLaunch at an AngleRange and Max HeightRecap - Hit the Target9Work and Energy
WorkKinetic EnergyWork-Energy TheoremGravitational PEConservation of EnergyPowerRecap - Roller Coaster12Impulse and Momentum
MomentumImpulseConservation of MomentumElastic CollisionsInelastic CollisionsRecap - Air Track15Simple Harmonic Motion
What is SHM?Mass on a SpringThe PendulumSHM GraphsEnergy in SHMRecap - Oscillator