Science lesson plan · 12th grade (Year 13 in England) · 45 minutes
Horizontal projectiles: time of flight and range
Forces and motion
CCSS NGSS.HS-PS2-1England: A level Physics: Projectile motion (extension)
Objective and success criteria
Students will: Horizontal projectiles: time of flight and range.
- 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: Uniform acceleration: v² − u² = 2 a s
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 · 5 min
- Quick retrieval from earlier learning (Uniform acceleration: v² − u² = 2 a s). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- An object starts at 4 m/s and accelerates uniformly at 2 m/s² over 5 m. What is its final velocity, in m/s? (Give 1 decimal place.) → 6 m/sPrompt: Use v² − u² = 2 a s.
- A car travelling at 20 m/s brakes with a deceleration of 5 m/s². What is its braking distance, in m? (Give 1 decimal place.) → 40 mPrompt: Final velocity v = 0.
- A train speeds up from 5 m/s to 20 m/s over 50 m. What is its acceleration, in m/s²? (Give 2 decimal places.) → 3.75 m/s²Prompt: a = (v² − u²) ÷ (2 s)
Hook · 5 min
- Drop a sheet of paper and a scrunched-up sheet together and ask why one falls faster.
- Share the objective: Horizontal projectiles: time of flight and range. 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 ball is kicked horizontally off a cliff 45 m high. Ignoring air resistance, how long does it take to reach the beach below, in s? (g = 9.8 m/s²; give 2 decimal places)
- Step 1: t = √(2 × 45 ÷ 9.8) = 3.03
- Step 2: So the answer is: 3.03 s
- Answer: 3.03 s
- 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 ball is kicked horizontally off a cliff 10 m high. Ignoring air resistance, how long does it take to reach the beach below, in s? (g = 9.8 m/s²; give 2 decimal places) → 1.43 sPrompt: Vertical motion starts from zero vertical velocity.
- A stone is thrown horizontally at 3 m/s from a cliff 19.6 m high. How far from the base of the cliff does it land, in m? (g = 9.8 m/s²; ignore air resistance) → 6 mPrompt: Find the time of flight from the vertical motion.
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.
- One ball is dropped and another is fired horizontally from the same height at the same moment. Which lands first (no air resistance)? (The dropped ball / The fired ball / It depends on their masses / They land at the same time) → They land at the same timePrompt: Horizontal and vertical motions are independent.
- A ball rolls horizontally off a table 1.2 m high. Ignoring air resistance, how long does it take to hit the floor, in s? (g = 9.8 m/s²; give 2 decimal places) → 0.49 sPrompt: Vertical motion starts from zero vertical velocity.
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: Uniform acceleration: v² − u² = 2 a s.
- 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-12.
Free lesson plan from eurekami.com/lesson-plan-builder