Science lesson plan · 10th grade (Year 11 in England) · 30 minutes
Momentum (p = m v)
Forces and motion
CCSS NGSS.HS-PS2-2England: GCSE Combined Science: Forces (momentum, Higher)
Objective and success criteria
Students will: Momentum (p = m v).
- 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: Force, mass and acceleration (F = ma); Scalars and vectors: distance vs displacement, speed vs velocity
Leads to: Conservation of momentum in collisions and explosions; Force and rate of change of momentum (safety design)
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 (Force, mass and acceleration (F = ma); Scalars and vectors: distance vs displacement, speed vs velocity). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- What resultant force is needed to accelerate a 2 kg mass at 2 m/s²? → 4 NPrompt: F = m × a
- Is energy a scalar or a vector quantity? (scalar (size only) / vector (size and direction)) → scalar (size only)Prompt: Does it make sense to give it a direction?
- A resultant force of 250 N acts on a 50 kg object. What is its acceleration, in m/s²? → 5 m/s²Prompt: Rearrange F = m a to find a.
Hook · 3 min
- Drop a sheet of paper and a scrunched-up sheet together and ask why one falls faster.
- Share the objective: Momentum (p = m v). 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: What is the momentum of a 5 kg object moving at 2 m/s, in kg m/s?
- Step 1: 5 × 2 = 10
- Step 2: So the answer is: 10 kgm/s
- Answer: 10 kgm/s
- 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.
- What is the momentum of a 0.5 kg object moving at 4 m/s, in kg m/s? → 2 kgm/sPrompt: momentum = mass × velocity
- An object of mass 80 kg has a momentum of 2000 kg m/s. What is its velocity, in m/s? → 25 m/sPrompt: Rearrange p = m v.
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.
- Two identical trolleys move towards each other at the same speed. What is their total momentum? (it cannot be worked out / double one trolley's momentum / half one trolley's momentum / zero) → zeroPrompt: Opposite directions have opposite signs.
- An object of mass 80 kg has a momentum of 480 kg m/s. What is its velocity, in m/s? → 6 m/sPrompt: Rearrange p = m v.
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: Force, mass and acceleration (F = ma).
- 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: Conservation of momentum in collisions and explosions; Force and rate of change of momentum (safety design).
- 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-10.
Free lesson plan from eurekami.com/lesson-plan-builder