3-Aut2-C

Outcomes

• Pupils can arrange all the GCSE quantities into two groups: scalars and vectors.
• Pupils appreciate that force is a vector quantity and understand the nature of this.

Specification References

• 1.10 distinguish between vector and scalar quantities
• 1.11 appreciate the vector nature of a force

Starter

• Introducing the idea of vectors to the class. Here are two options.
• 1) Hide a £1 coin/chocolate bar/whatever you like a set distance from a pre-determined place in the classroom. Stand on this spot with a stop watch. Choose two students and tell them "There is a £1 coin 2 meters from my current position. If you can find it within 6 seconds it's yours!" Stop the students after the 6 seconds. Encourage the students to discuss your statement. Is there enough information included in the statement to find the £1 coin? The displacement required to find the coin has not been fully described. Now, tell them " There is a £1 coin 2 meters and directly North of my current position, start the stop watch again. They will hopefully find the coin this time. You could even tape it to the ceiling if you wish! This statement now provides a complete description of the displacement vector - it lists both magnitude (2 meters) and direction (North) relative to a reference or starting position. Vector quantities are not fully described unless both magnitude and direction are listed.
• 2) Ask the pupils to estimate the number of steps you need to take to reach the back of the classroom. Once you have an agreed number of steps from the class begin walking to the back of the room (counting the number of steps as you go along) but walk in and out of the desks. Question how the pupils could have gotten it so wrong and begin to introduce the terms distance and displacement and how vector quantities are not fully described unless both magnitude and direction are given.

Main Body of Lesson

• Split the class into groups and give each group a pack of cards which contain all the GCSE quantities. Ask them to divide them into two groups: 1) those that have a direction and can be represented with an arrow (a vector) and 2) those that do not (a scalar).
• Discuss the groups outcomes and write definitions for vectors and scalars to be recorded in their books. Emphasise that vector quantities could be negative whereas scalar quantities cannot.
• They may argue about temperature where they can be introduced to the Kelvin scale
• They may also quibble charge, there is no direction involved so they are not vectors
• Move on to focus about forces. Ask group how we could represent the forces acting on an object resting on a table
• Explain that force vectors are depicted as arrows to show the direction, with the length of the arrow representing the magnitude of the force. You could introduce the 'head' and 'tail' of the force vector.

Homework

• Vector Addition Map Game - All of the rules and instructions are now on the sheet
• Students could also research the difference between speed and velocity and how the change in velocity can occur by the velocity only changing direction and not magnitude. This could lead them to the idea of circular motion.

Resources Required

• Class set of quantity cards in envelopes + whiteboards
• Class set of mini whiteboards

Textbook References

• None

Website References

• None

Safety/Hazards

• None

Notes

• None