Uniform circular motion
The speed stays the same, so why is the velocity still changing?
When an object moves along a circle, its velocity always points along the tangent and the centripetal force always points toward the center. "Uniform" means the speed is constant; the direction of the velocity keeps changing.
Horizontal position vs. time
Think about it
Keeping the radius and mass constant, if the speed is doubled, what does the centripetal force become?
It becomes 4 times as large, because the centripetal force F = mv²/r is proportional to the square of the speed; meanwhile, the period is halved.
Model assumptionsIdeal uniform circular motion · green arrow: velocity, red arrow: centripetal force · arrow lengths are not to scale
Data log
Set the parameters and click “Record data”. Record several rows with different parameters to plot their relationship and fit a straight line; pause and record at different times to study how a reading changes with time.