Crash Test Lab
A free kinetic energy simulation. What makes a crash more dangerous, a heavier vehicle or a faster one? Students crash 14 vehicles into Kyle the crash test dummy and let the data decide.
What students do
Students start by making a hypothesis: is it more dangerous to double a vehicle's mass, or to double its speed? Then they run two controlled experiments. Kyle, a crash test dummy, sits in his car parked in front of a concrete crash wall. In Part 1, seven remote-controlled vehicles hit him at the same speed (18 m/s, about 40 mph), and each one has double the mass of the last: a go-kart, a golf cart, a tiny car, a sedan, a pickup truck, a box truck, and a city bus. In Part 2, the same 1,600 kg sedan hits him seven times, and its speed doubles every time, from a 0.5 m/s crawl up to 32 m/s (about 72 mph).
Before every crash, students calculate the vehicle's kinetic energy with KE = ½mv². Then the vehicle backs up to a start line as far as 60 meters away, waits for a countdown light, and races in while the camera follows it past distance markers and a speed gate. After the crash, a damage report shows the energy released, the damage to both vehicles, and Kyle's estimated survival chance, while their data table and graphs fill in. At the end, students analyze the patterns, write a conclusion, check their hypothesis, and screenshot a finished worksheet to turn in.
Students predict whether doubling the mass or doubling the speed is more dangerous, and explain why.
Same speed every time. A new vehicle each trial, each one twice as heavy as the last.
Same sedan every time. Its speed doubles each trial, from a crawl to highway speed.
Pattern questions, a written conclusion, a hypothesis check, and a one-screen worksheet.
The science behind Crash Test Lab
Kinetic energy
KE = ½ × m × v². Kinetic energy is the energy of motion. Mass is in kilograms, speed in meters per second, and energy in joules.
Every vehicle in the lab is designed so students can see the two relationships cleanly. In Part 1 the mass doubles every trial: 200, 400, 800, 1,600, 3,200, 6,400, and 12,800 kg. The kinetic energy doubles right along with it, from 32,400 J to 2,073,600 J, and the KE vs. mass graph is a straight line through zero. Kinetic energy is directly proportional to mass.
In Part 2 the speed doubles every trial: 0.5, 1, 2, 4, 8, 16, and 32 m/s. This time the kinetic energy goes up by 4 times with each doubling, from 200 J to 819,200 J, and the KE vs. speed graph curves upward. Because speed is squared, doubling it gives 2 × 2 = 4 times the energy. Over the whole lab, a 64-fold increase in mass multiplies KE by 64, but a 64-fold increase in speed multiplies it by 4,096.
Where the energy goes
Energy is not created or destroyed. In a crash, kinetic energy transfers into other forms.
Kyle's car is parked with its back against a concrete crash wall, so each crash stops everything right away. All of the striking vehicle's kinetic energy is transferred into crushed metal (the crumple zones), broken glass, flying pieces, sound, and heat. Live labels point to each one after the crash. Both front ends crush by realistic amounts: the vehicles act like springs pressed together, so softer fronts absorb more of the energy.
Why speed is so dangerous
The lab ends with the real-world takeaway: a vehicle going twice as fast carries four times the energy, so a crash at 60 mph is about four times as violent as one at 30 mph, and the car needs about four times the distance to stop. The damage report turns crash energy into a survival estimate for a real person wearing a seat belt. These numbers are clearly labeled as estimates, but they always follow the energy: more joules, more danger.
NGSS alignment
Crash Test Lab is built around performance expectation MS-PS3-1.
| Standard | What it says | How the simulation supports it |
|---|---|---|
| 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. | Students build two data tables and two graphs as they crash, KE vs. mass and KE vs. speed, then interpret them: a straight line for mass and an upward curve for speed. |
| MS-PS3-5 | 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. | Every crash shows the vehicle's kinetic energy transferring into crushed metal, sound, and heat, with live labels and a damage report. |
| DCI PS3.A | Motion energy is properly called kinetic energy; it is proportional to the mass of the moving object and grows with the square of its speed. | This is the exact finding students reach in the pattern questions and their written conclusion. |
| Practices | Planning and Carrying Out Investigations; Analyzing and Interpreting Data; Using Mathematics and Computational Thinking | Students identify independent, dependent, and controlled variables, calculate KE 14 times, and use their data to support a claim. |
| Crosscutting concept | Scale, Proportion, and Quantity | Proportional (×2) vs. squared (×4) relationships, and energies from 200 J to over 2 million J. |
How to use it in class
- Hook (3 min). Ask: "Would you rather be hit by a car that's twice as heavy or one that's going twice as fast?" Take a quick vote.
- Hypothesis (3 min). Students open Lab Mode and type their hypothesis with a reason.
- Part 1 and Part 2 (25 min). Students calculate KE before each of the 14 crashes. The calculator is built in, and wrong answers get targeted hints (forgot the ½, didn't square the speed, used mph).
- Analyze (7 min). Students answer six pattern questions, write a conclusion, and decide whether their hypothesis was supported.
- Submit (1 min). Students screenshot their finished worksheet and turn it in.
- Debrief (5 min). Use the discussion questions below.
Discussion questions
- Why do we change only one variable at a time? What would go wrong if the mass and the speed both changed in the same trial?
- The bus crash had the most energy of all 14 crashes. Does that mean mass is more dangerous than speed? Explain using the patterns in your data.
- If a car speeds up from 30 mph to 60 mph, how many times more kinetic energy does it have? What about 30 to 90 mph?
- Where did the kinetic energy go after each crash?
- Why are speed limits lower near schools and neighborhoods?
Key vocabulary
Kinetic energy, joule (J), mass, speed, hypothesis, independent variable, dependent variable, controlled variable, directly proportional, squared, energy transfer, crumple zone.
Frequently asked questions
Is Crash Test Lab free?
Yes. It runs free in any web browser with no ads, no download, and no login.
What do students turn in?
A screenshot of their finished worksheet. It shows their name, the date, an ID, their typed hypothesis, both data tables and graphs, the patterns they found, their typed conclusion, and whether their hypothesis was supported, all on one screen.
Why is Kyle's car parked against a wall?
So the crash stops everything right away. That way, all of the striking vehicle's kinetic energy goes into the crash as bent metal, broken glass, sound, and heat, which makes the vehicle's kinetic energy a fair measure of how much damage each crash can do.
Are the survival chances real?
They are labeled as estimates. The simulation turns crash energy into a rough survival estimate for a real person wearing a seat belt with an airbag, so that more energy always means more danger. Real crashes also depend on the angle, the car's safety features, and luck. The kinetic energy numbers themselves are exact.