STUCK IN PHYSICSAll simulationsBlock on an incline
IB Physics SL & HL · A Level Physics · AP Physics 1 · AP Physics C: Mechanics
Tilt the plane. Find the tipping point between rest and sliding. Explore normal contact force, friction, weight components, resultant force and acceleration directly on the moving block.
Set up the incline
Use the mass slider above to change the block’s mass; the block itself stays unlabelled. We keep μₖ ≤ μₛ. Changing a setting releases a fresh block from rest. Gravity: 9.81 m s−2.
The largest angle at which this block can remain at rest in the ideal static-friction model.
Rest or slide?
Schematic track with an 8 m observation length. Playback fits the observation into 10 screen seconds; numerical values show physical time. Motion beyond the bottom of the ramp is not modelled.
Angle of repose
As the angle increases, the downhill component of weight increases and the normal contact force decreases. At the limiting angle, the required static friction equals its maximum value.
At exactly the angle of repose, this ideal model can remain at rest. Increase the angle slightly and the block slides, so kinetic friction applies. The angle of repose depends on μₛ, not the mass or μₖ.
Once the block slides
Static friction adjusts to the value needed to hold the block, up to its limit. It is not always μₛN. During sliding, kinetic friction has magnitude μₖN and acts up the plane because the block moves down it.
Try increasing the mass: the forces increase, but the acceleration and angle of repose stay the same. Then set μₖ to zero and compare the acceleration with a smooth incline.
Model: rigid block released from rest, fixed horizontal-support incline, ideal dry friction, no air resistance or rotation. The incline stays fixed during each trial; changing controls resets the block. Angle-of-repose detail is an extension where a course does not explicitly require it.
Explore forces on an inclined plane
Change the incline angle, block mass and static and kinetic friction coefficients. Switch between actual forces, resolved weight, resultant force and acceleration, with vectors attached directly to the moving block.
Supports mechanics topics in IB Physics SL and HL, A Level Physics, AP Physics 1 and AP Physics C: Mechanics. The angle-of-repose controls provide an extension where a course does not explicitly require that terminology.