Science lesson plan · 9th grade (Year 10 in England) · 30 minutes
Stopping distances: thinking and braking
Forces and motion
CCSS NGSS.HS-PS2-1CCSS NGSS.HS-ETS1-2England: GCSE Combined Science: Forces (stopping distance)
Objective and success criteria
Students will: Stopping distances: thinking and braking.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Speed = distance ÷ time; Acceleration
Leads to: the next skill in this area.
Materials: Force meters, Toy cars and ramps, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 4 min
- Quick retrieval from earlier learning (Speed = distance ÷ time; Acceleration). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- A cyclist travels 80 m in 4 s. What is the average speed, in m/s? → 20 m/sPrompt: speed = distance ÷ time
- A car speeds up from 2 m/s to 42 m/s in 10 s. What is its acceleration, in m/s²? → 4 m/s²Prompt: acceleration = change in velocity ÷ time taken
- A car travels at an average speed of 120 km/h for 3 hours. How far does it travel, in km? → 360 kmPrompt: distance = speed × time
Hook · 3 min
- Drop a sheet of paper and a scrunched-up sheet together and ask why one falls faster.
- Share the objective: Stopping distances: thinking and braking. Read the success criteria together.
I do: model it · 7 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: A driver travelling at 25 m/s has a reaction time of 0.7 s. What is the thinking distance, in m?
- Step 1: 25 × 0.7 = 17.5
- Step 2: So the answer is: 17.5 m
- Answer: 17.5 m
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 6 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- A driver travelling at 25 m/s has a reaction time of 0.7 s. What is the thinking distance, in m? → 17.5 mPrompt: During the reaction time the car keeps moving at the same speed.
- A car's thinking distance is 18 m and its braking distance is 6 m. What is the overall stopping distance, in m? → 24 mPrompt: stopping distance = thinking distance + braking distance
You do: independent practice · 7 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 6 questions are on the student sheet below, with answers in the key.
Exit ticket · 3 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- A driver travelling at 30 m/s has a reaction time of 0.5 s. What is the thinking distance, in m? → 15 mPrompt: During the reaction time the car keeps moving at the same speed.
- Which part of the stopping distance is increased mainly by this: a driver who has drunk alcohol? (thinking distance / braking distance) → thinking distancePrompt: Is it about the driver or about the car and road?
Watch out for
- Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
- Remembering facts without the reason: ask "why?" and "what is the evidence?"
Support and stretch
Support
- Review first: Speed = distance ÷ time.
- Use concrete materials: force meters.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-9.
Free lesson plan from eurekami.com/lesson-plan-builder