Regen Braking Lab — Tuva

Cargo load

Speed

40 km/h

Playback

Results

Choose a load and a speed, then start the run.

No runs logged yet

Reset the lab?

The lab will return to its starting state. What should happen to the runs you’ve logged so far?

Regen Braking Lab

Load an electric delivery truck, set its speed, and run a standard regenerative-braking stop. The console reports the energy captured into the battery — log runs to discover how the energy of motion depends on mass and on speed.

Data format

Each logged run records the speed (km/h), the total mass from the yard scale (t), the energy the battery captured (kJ), and the stopping distance (m). Sweep one setting while holding the other still, then plot Energy captured against that setting to see the pattern.

Model details

Metric units throughout: tonnes, km/h, meters, kilojoules.
The standard test is a one-pedal maximum-regeneration stop: the friction brakes stay out, so the captured energy stays proportional to the truck’s energy of motion.
The meter reports a fixed share — about 72% — of the truck’s energy of motion; the remainder leaves as heat in the motor and drivetrain.
The test uses a constant braking force, so the stopping distance grows in step with the energy of motion.
With the same braking force, a heavier truck slows more gently — a full load makes a long, gradual stop. Watch the speed readout fall.
Playback (1×, 2×, 4×) changes only how fast a run plays back — never the measurements.
Readings vary by a few percent run to run, like real measurements.
One idealized truck on a flat, dry test track; air and rolling resistance are ignored.

Standards

MS-PS3-1 — Construct and interpret graphical displays of data to describe the relationships of kinetic energy to the mass of an object and to the speed of an object.
MS-PS3-5 (supporting) — Construct, use, and present arguments to support the claim that when the kinetic energy of an object changes, energy is transferred to or from the object.

Design intent

Mass and speed are the only two settings, changed independently — investigating them separately is the sim’s protocol, matching the standard’s clarification statement.
The energy value comes from a real instrument: an electric vehicle measures the energy its regenerative brakes return to the battery. The sim surfaces that per-stop number the way a fleet engineering console would.
The meter reports a fixed share (about 72%) of the truck’s kinetic energy — deliberately not 100%, so students meet the truth that no energy transfer is ever complete. Where the rest goes is a discussion prompt, not a defect.
Stopping distance rides along as a second reading students can verify with their own eyes, corroborating the meter. The sim never states the relationships; students construct them from runs they logged themselves.

Discussion prompts

What evidence shows the loaded truck carries more energy than the empty one at the same speed?
Doubling the speed far more than doubles the captured energy. What does the graph suggest the pattern is?
The battery captures only about three-quarters of the truck’s energy of motion. Where does the rest go?
Why might a delivery company care how much energy each stop returns to the battery?

How do I explore?

Choose a cargo load — the yard scale shows the truck’s total mass.
Choose a speed, then press Start Run and watch the console as the truck brakes — the speed falls as the energy climbs.
Read the energy captured and the stopping distance in the Results card, then press Log this run.
Change one setting at a time and run again. Repeating a run is a good idea — readings vary a little, just like real measurements.

What should I do/notice?

Double the total mass at the same speed. What happens to the energy captured?
Double the speed with the same load. Does the energy double too? Look carefully.
The battery never catches quite all of the truck’s energy of motion. Where might the rest go?

What about the data?

Each logged run saves the speed, the total mass from the scale, the energy the battery captured, and the stopping distance. Sweep one setting while holding the other still, then plot Energy captured against that setting to see the pattern.