Labs / Physics
Friction Ramp
Drag right on the ramp to tilt it steeper, or use the angle slider. The block holds still while static friction can match the pull of gravity down the slope — keep tilting and, the instant it can't, the block breaks loose and slides. The arrows are a live free-body diagram of every force in play.
mg sinθ 0 Nfs,max 0 NHolding
What to try
- On wood (μ = 0.35), how steep does the ramp have to get before the block finally slips?
- Does making the block heavier change the angle at which it starts to slide — and can you see why in the arrows?
- Switch to ice. Can the block ever hold still, or does it slip almost immediately?
- Turn off "Kinetic < static". Once moving, does the block speed up faster or slower?
- Find the exact angle where mg sinθ just equals fs,max. What is special about tan of that angle compared to μ?