Science lesson plan · 3rd grade (Year 4 in England) · 45 minutes
Which way will it move? Predict from the forces
Forces and motion
CCSS NGSS.3-PS2-1England: KS2 Y3 Forces and magnetsEngland: KS3 Physics: Motion and forces (balanced forces)
Objective and success criteria
Students will: Which way will it move? Predict from the forces.
- 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: Balanced and unbalanced forces
Leads to: Tug of war: add up forces and find the winner; Use patterns of motion to predict what happens next; Contact forces and forces that act at a distance
Materials: Force meters, Toy cars and ramps, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Balanced and unbalanced forces). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Balanced forces: which statement is NOT true? (When forces are balanced, a still object stays still. / Forces are measured in newtons (N). / A book resting on a table has balanced forces acting on it. / Forces are measured in kilograms.) → Forces are measured in kilograms.Prompt: Can something move steadily with balanced forces?
Hook · 5 min
- Drop a sheet of paper and a scrunched-up sheet together and ask why one falls faster.
- Share the objective: Which way will it move? Predict from the forces. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: A cyclist pedals harder than the air and road push back. What happens?
- Step 1: Unbalanced forward force makes the bike speed up.
- Step 2: So the answer is: The bike speeds up.
- Answer: The bike speeds up.
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 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 rolling ball slows down and stops on grass. Which force caused this? (magnetism / a push from the ball / no force, it just ran out / friction from the grass) → friction from the grassPrompt: Something acted against the motion.
- True or false? A book on a table has no forces acting on it. (True / False) → FalsePrompt: Compare the sizes and directions of the forces.
You do: independent practice · 10 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 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- A cyclist pedals harder than the air and road push back. What happens? (The bike stays at exactly the same speed. / The bike speeds up. / The bike moves backwards. / The bike slows down.) → The bike speeds up.Prompt: Which way is the bigger force?
- True or false? An object with balanced forces must be still. (True / False) → FalsePrompt: Compare the sizes and directions of the forces.
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: Balanced and unbalanced forces.
- 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
- Move on to: Tug of war: add up forces and find the winner; Use patterns of motion to predict what happens next; Contact forces and forces that act at a distance.
- 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-3.
Free lesson plan from eurekami.com/lesson-plan-builder