Lab Duel

A card game for 2–4 players where the only way to win is to use the science correctly.

Setup

Shuffle the concept cards. With the small prototype deck (10 cards), deal 2 cards each to 4 players (or 3 each for 2–3 players). Put the three challenge cards face down. A larger deck can deal 5 each.

A round

Turn over a challenge: a real situation. On your turn, play a card that solves it, call “Spark on!” and explain why in one sentence. If you can, say a number. If you cannot play, pass or redraw one card from the remaining deck (then discard one) once per turn.

Scoring

Flip the challenge: its back lists the accepted cards. Right card and a sensible explanation: you keep the challenge (1 point; two accepted cards together score 2). With only three challenges in the prototype, highest score after all challenges wins; ties share the win or play a sudden-death rematch challenge if you have more. First to 5 is for a larger reusable challenge deck.

The first three challenges

ChallengeLab Duel
Stop a car doing 20 m/s within 30 m on a level road.
What braking does it take, and is it possible?
Play a card that solves it and say why in one sentence.
SPARKONC1
Accepted answers
C1
Newton's second lawEnergy conservation
Two of these together score double.
A winning explanationBraking must remove the car's movement energy ½mv² over 30 m, so it needs about 6.7 m/s² of steady braking (F = m · a: about 8 kN for a 1,200 kg car). Tyres give that only with good grip, roughly μ ≥ 0.68: possible on a good dry road, not on ice. Ignores reaction time.
a = v² / (2s) = 400 / 60 ≈ 6.7 m/s²
Close enough counts: the other players decide if the explanation is right.

Stop a car doing 20 m/s within 30 m on a level road.

What braking does it take, and is it possible?

Think first, then flip the card (click, tap, or Enter/Space) — or read the answer below.

Accepted cards: Newton's second law · Energy conservation (together score double).

A winning explanation

Braking must remove the car's movement energy ½mv² over 30 m, so it needs about 6.7 m/s² of steady braking (F = m · a: about 8 kN for a 1,200 kg car). Tyres give that only with good grip, roughly μ ≥ 0.68: possible on a good dry road, not on ice. Ignores reaction time.

a = v² / (2s) = 400 / 60 ≈ 6.7 m/s²

ChallengeLab Duel
Why does ice float on a lake?
Explain it so a friend could predict it.
Play a card that solves it and say why in one sentence.
SPARKONC2
Accepted answers
C2
Density
Only one card fits this one.
A winning explanationIce (0.92 g/cm³) is less dense than water (1.00 g/cm³), so it floats. Going deeper: when water freezes, hydrogen bonds between its molecules lock them into an open pattern with more space.
0.92 < 1.00 → floats, about 9/10 under water
Close enough counts: the other players decide if the explanation is right.

Why does ice float on a lake?

Explain it so a friend could predict it.

Think first, then flip the card (click, tap, or Enter/Space) — or read the answer below.

Accepted card: Density. The deeper reason (hydrogen bonds) is a bonus, not a second card.

A winning explanation

Ice (0.92 g/cm³) is less dense than water (1.00 g/cm³), so it floats. Going deeper: when water freezes, hydrogen bonds between its molecules lock them into an open pattern with more space.

0.92 < 1.00 → floats, about 9/10 under water

ChallengeLab Duel
Will a 5 m ladder reach a window 4 m up if its foot must stand 3 m out?
Yes or no, and prove it.
Play a card that solves it and say why in one sentence.
SPARKONC3
Accepted answers
C3
Pythagoras' theorem
Only one card fits this one.
A winning explanationThe ladder is the long side: 3² + h² = 5², so h² = 16 and h = 4 m. It reaches exactly to the window sill, with nothing to spare.
√(25 − 9) = √16 = 4 m
Close enough counts: the other players decide if the explanation is right.

Will a 5 m ladder reach a window 4 m up if its foot must stand 3 m out?

Yes or no, and prove it.

Think first, then flip the card (click, tap, or Enter/Space) — or read the answer below.

Accepted cards: Pythagoras' theorem only.

A winning explanation

The ladder is the long side: 3² + h² = 5², so h² = 16 and h = 4 m. It reaches exactly to the window sill, with nothing to spare.

√(25 − 9) = √16 = 4 m