Car Physics: Crashes & Traction

Name:

Date:

📚 Part 1: Crashes — Multiple Choice

WALT: We are learning to explain why crashes are dangerous and identify factors that affect crash severity.

Success criteria: I can (1) name key quantities (e.g. momentum, force), (2) identify safety features that reduce injury, and (3) list factors that change braking distance.

Differentiation:
- Support: read questions aloud; eliminate two options first.
- Challenge: explain why your chosen answer is best in one extra sentence.
- Mixed-age: give the 8-year-old a simpler version of Q2 to match understanding.

1. Which physical quantity best describes how hard a car hits in a crash?

Force (newtons)

Momentum (kg·m/s)

Acceleration (m/s²)

Mass (kg)

2. Which safety feature(s) reduce injury in a crash?

Seatbelt

Airbag

Crumple zones

All of the above

3. Check all factors that affect braking distance:

Vehicle speed

Tyre grip / tread condition

Road surface (wet or dry)

Driver's age

4. In a collision where two cars stick together after impact, which quantity is conserved?

Kinetic energy

Speed

Momentum

None of these

✏️ Part 2: Short Answers, Calculations & Drawing

WALT: We are learning to calculate momentum and stopping distance, and describe how traction helps prevent crashes.

Success criteria: I can (1) convert km/h to m/s, (2) calculate momentum and stopping distance with units, and (3) explain how tyres and safety features reduce forces.

Differentiation:
- Support: use a calculator and a conversion hint (1 km/h = 0.2778 m/s).
- Challenge: change values to compare two different speeds and comment on differences.
- Mixed-age: give the younger child a simpler number to convert (e.g. 10 km/h).

5. Calculate the momentum of a 1,200 kg car travelling at 50 km/h. Show your working and give your answer with units.

6. A car travelling at 50 km/h brakes with an average deceleration of 6 m/s². Estimate the stopping distance using s = v² / (2a). Show conversions and working.

7. Explain in 2–3 sentences how seatbelts and crumple zones reduce the force on a person during a crash.

8. Draw a tyre tread (side view or top view) and label two features that improve traction. Explain briefly why each helps.