Mr Di Lizio · Head Mechanic
This dragster is built like a tank — way too heavy. The CO₂ cartridge always pushes with the same force, so the heavier the car, the slower it accelerates. We need to trim weight… but be careful. Go too light and the car gets fragile and tippy. Mass is all about finding the sweet spot.
F = m × aSAME push (F) ÷ LESS mass (m) = MORE acceleration (a)
That's Newton's second law. The CO₂ force F is fixed, so to get more acceleration a, you cut the mass m. But a real engineer balances speed against durability and stability.
⏱ ~4 min⚖️ 3 weigh-in missions🎯 Find the sweet spot
Mission 1 of 3 · Trim
Too heavy to launch
WEIGH-IN · F = m × a
🧑🔧
Mr Di Lizio
Slide it from heavy toward light and watch the acceleration climb. But keep an eye on the durability meter — hollow it out too far and it'll snap when the cartridge fires. Find the line where it's light AND still strong.
⚖️ Mass
—
🚀 Acceleration
—
🛡️ Durability
—
✂️Trim the massHUGE EFFECT
Hollow out the body and remove spare material. Lighter = faster… until it becomes too fragile to survive the launch.
heavytoo light
Far too heavy — the CO₂ can barely move it.
Mission 2 of 3 · Reinforce
It keeps cracking
WEIGH-IN · DURABILITY
🧑🔧
Mr Di Lizio
Smart engineers don't just remove weight everywhere. They keep a lightweight core but add small reinforcements where the force hits hardest — around the cartridge and axle holes. That way you stay light AND strong. Add just enough bracing.
⚖️ Mass
—
🚀 Acceleration
—
🛡️ Durability
—
🛡️Reinforce the weak pointsBIG EFFECT
Add targeted bracing at the cartridge chamber and axle holes — barely any weight, but it stops the car shattering on launch.
no bracebraced
No reinforcement — fragile around the cartridge.
Mission 3 of 3 · Balance
The car wobbles
WEIGH-IN · BALANCE
🧑🔧
Mr Di Lizio
The weight is bunched up at one end, so the car wobbles and veers off the line — that wastes speed. Spread the mass evenly and keep the centre of mass low. Slide it from lopsided to balanced and watch it run straight.
⚖️ Mass
—
🚀 Acceleration
—
🎯 Stability
—
🎯Balance the weightSTABILITY
Spread the mass evenly and low along the body so the car tracks straight instead of wobbling off the guide line.
lopsidedeven & low
Weight bunched at one end — car wobbles.
Weigh-In Test
Question 1 of 4
Sweet Spot Found
Light, Strong, Stable
WEIGH-IN · F = m × a
2.60 s
↓ 1.40s faster than the heavyweight
What you learned about mass
1Lighter accelerates faster. Same CO₂ force ÷ less mass = more acceleration. F = m × a is the whole game.
2But don't overdo it. Too light and the body cracks under the cartridge force — there's a sweet spot, not "lightest wins."
3Reinforce smartly. Keep a light core, brace only the high-stress spots (cartridge & axles). Strong AND light.
4Balance the weight. Spread mass evenly and low so the car runs straight instead of wobbling and losing speed.
🧑🔧
Mr Di Lizio
Golden rule: as light as you can get away with — but no lighter. A car that shatters at the line finishes last. You've now got Friction and Mass. One more module to go — Aerodynamics.