1. VECTORS, SCALARS AND VECTOR ADDITION YEAR 12 UNIT 1 MODULE 1 LESSON 2

2. As physicists, when do we and don’t we need to know about direction? Discuss – in pairs or 3’s.

3. Lesson Objective: To learn the difference between scalars and vectors and be able to categorise physical quantities as one or the other. 1.1.2 Scalars and vectors Define scalar and vector quantities and give examples. Draw and use a vector triangle to determine the resultant of two coplanar vectors such as displacement, velocity and force. Calculate the resultant of two perpendicular vectors such as displacement, velocity and force. Resolve a vector such as displacement, velocity and force into two perpendicular components.

4. ADMIN STUFF Nick.mason@oasisenfield.org – email me if you need anything. Or come see me – I’m mostly in C5 Nick.mason@oasisenfield.org www.physics-oasis.com – Timetable, Exam questions, Presentations etc. www.physics-oasis.com Homework will be set at least once a week – probably on Friday this week.

5. CONVERTING UNITS OF AREA AND VOLUME

6. 10,000cm 2 1m =100 cm 1m 2 = 10,000cm 2 = 10 4 cm 2 1 cm 2 = 1/10 4 m 2 = 10 -4 m 2 1 m is 100cm, However 1m 2 is 10000cm 2 – Why? Each side must be converted to centimetres before finding the area.

7. 1000 000mm 2 1m =1000 mm 1m 2 = 1 000 000mm 2 = 10 6 mm 2 1mm 2 = 1/ 10 6 m 2 = 10 -6 m 2

8. 1m =100 cm 1m 3 = 1 000 000cm 3 = 10 6 cm 3 1 cm 3 = 1/10 6 m 2 = 10 -6 m 2 100 00 00cm 3 1m= 100 cm

9. 1m =1000 mm 1m 3 = 1 000 000 000mm 3 = 10 9 mm 3 1mm 3 = 1/ 10 9 m 3 = 10 -9 m 3 1000 000 000mm 3 1m =1000 mm

10. ? mm 3 5m 3 1m 3 Find the volume of the cuboid in mm 3

11. 1m100cm1000mm 1m 2 100cm x100 cm = 10,000cm 2 = 10 4 cm 2 1000mm x 1000mm= 1,000 000 m 2 =10 6 m 2 1m 3 100cm x 100cm x 100cm =1,000,000 cm 3 = 10 6 cm 3 1000 mm x 1000mm x 1000 mm = 1000000000 mm 3 = 10 9 mm 3 1mm0.001m =10 -3 m 1mm 2 10 -6 m 2 1mm 3 10 -9 m 3

14.  How big would all the world’s data be?  http://www.businessinsider.com/infographic-how-big-would- all-the-worlds-data-be-2012-8 http://www.businessinsider.com/infographic-how-big-would- all-the-worlds-data-be-2012-8  Short answer: about 10 ZettaBytes

16. Scalar: A quantity that is defined only by a magnitude Vector: A quantity that has both direction and magnitude

17.  Sort the following physical quantities into scalars and vectors: Velocity, Force, Speed, Distance, Displacement, Acceleration, Kinetic Energy, Gravitational Potential Energy, Weight, Potential Difference (Voltage), Time, Electric Current, Electric Charge.  Extension: If you are familiar with them, try adding these quantities: Electric Field, Wavelength, Frequency.  Extension 2: Add any quantities of your own, that I have missed off.

18. When two or more vectors are added the resulting sum of the vectors is called the RESULTANT vector or simply the RESULTANT. This could be a resultant velocity, force, acceleration etc. depending on the nature of the original vectors.

19. (i) vectors acting in the same line Two or more vectors acting in the same direction may be added as if they were scalars. For example the sum, or resultant of the three forces shown in Fig. 1(a) is 50 N acting right to left while in (b) it is 250 N left to right