Set up a trial
Changing angle or friction resets the trial.
Marks follow simulated time at every playback speed.
s
m
m/s
m/s²
LIVE MOTION
Down the inclined plane
Separate fixed arrow scales: V, 4 drawing units per m/s; a, 8 per m/s². Compare each arrow with itself over time.
EQUAL TIME INTERVALS
One-second motion record
Each black dot marks the position after another 1 s.
One-second sample Arrival between seconds
The release dot is the t = 0 reference. A hollow arrival marker is an endpoint, not another one-second sample.
THE SAME RECORD, IN NUMBERS
Recorded data
1 record · release
| Time t (s) | Distance along ramp s (m) | Velocity V (m/s) | Friction coefficient μ | Acceleration a (m/s²) |
|---|
An arrival row will complete the record. μ has no units.
Explore and reflect Predict · test · improve
ALLI can identify velocity and acceleration.
MOSTI can use the recorded data to connect acceleration with changing velocity.
SOMEI can explain how angle and friction affect motion and the spacing of the marks.
Success criterion My explanation connects the change in settings to acceleration and to evidence from the marks or data.
DOK 1 · Identify [Pair]
Find V and a. Which arrow changes during one sliding trial?
DOK 2 · Check [Individual]
Use two recorded values to check a prediction and revise the explanation using evidence.
DOK 3 · Explain [Pair]
Predict how increasing the angle will change the motion record, then compare trials while holding friction constant.
Early finishers [Individual]
Find the smallest whole-degree angle that starts motion for a chosen nonzero friction setting, then explain the boundary.
Choose which two angles to compare. Use the success criterion to identify one strength or misconception, then complete a correction and test it in a new trial.
You can revisit and correct these responses in this tab. Nothing is submitted or saved by the app; reloading clears them. You may explain aloud or on paper. Take additional time as needed.
About the model Physics · formulas · assumptions
A particle slides from rest along a 20 m plane. Positive direction is down the ramp. g = 10 m/s². Angle and friction remain fixed during each trial. Air resistance and rotation are excluded; the dot’s radius is only a visual marker.
This introductory model uses the same coefficient for static and sliding friction. Real surfaces can have different coefficients.
q = sin θ − μ cos θ
If q ≤ 0: a = 0, V = 0, s = 0
If q > 0: a = g(sin θ − μ cos θ)
s = ½at² · V = at · Vi = 0
T = √(2L ÷ a) · Varrival = √(2aL)
To suppress numerical noise at the static boundary, q ≤ 10−12 is treated as rest. Time and position use analytical formulas with full precision; only displayed values are rounded.
The observation ends exactly at s = 20 m. The frozen final V and a are the values immediately before arrival. Ending the animation does not model a collision or mean that the particle physically stops.
The sheet measures distance along the ramp, using the same 0–20 m scale in every trial. Black marks and table rows use the same exact sample records. Close marks remain close. Arrival times use extra decimals to distinguish arrival from an integer-second sample.
Playback changes the viewing pace. It does not change acceleration, sample positions or arrival values. Switching away from the page pauses a running trial; choose Resume when you return.