Vectors vs. ScalarsPop Quiz: Which of these do you think are vector quantities?

Mass, Temperature, Distance, Displacement, Speed, Velocity,

Acceleration, Force, Work, Energy, Power, Momentum, Time

• A vector is an arrowed line.

• A vector has a tail and a head.

• The head points in the direction of the vector.

• The length represents the size (magnitude) of the vector.

Represent these displacements as vectors on your bookUse scale 1:100 (i.e. 1cm on your book is equivalent to 1m in real)

1. Jimmy travels 13 m west.

2. Bobby travels 3 m south.

3. Timmy travels 6 m, 45o north of east.

4. Libby travels 5 m, 80o north of west.

A = 030o

B = 300o

C = 110o

D = 260o

Bearing

048o 240o

140o 290o

The bearing of A from B is 065o.

The bearing of B from A is 245o.

Vector Addition

Vector A = 7 m towards east

Vector B = 4 m towards north

Vector A + B = ???

Adding Vectors(to find the resultant vector)Q1. A car travels 3 km east, then 4 km south. Find the car’s total displacement by drawing a scaled vector diagram.

Q2. During a tug-of-war, the rope is pulled with a force of 250 N towards left and a force of 300 N towards right. Find the resultant force acting on the rope.

Negative Vector

Vector A = 7 m towards east

Question: What would be the negative vector A?

Answer: 7 m towards west

Vector SubtractionVector subtraction is the same as the vector addition, only adding a negative vector.

A – B = A + -BVector A = 7 m towards eastVector B = 4 m towards northVector A – B = ???

Vector Subtraction(to find the change, Δ = f – i)Q1. A car initially travelling at 15 ms-1 east turns a 90o corner and ends up travelling at 10 ms-1 north. Determine the change in velocity by using a vector diagram.

Q2. A ball initially travelling towards a batman at 5 ms-1 collides with him and rebounds at 4 ms-1 in the opposite direction. Find the ball’s change in velocity.

Do all questions from Activity 8A (green textbook, pg. 98) except for Q9.

Do nowVector A = 4 cm eastVector B = 4 cm northVector C = 6 cm westVector D = 5 cm bearing 45O

Draw vector diagrams to show:1. A + B 5. A – B2. C + D 6. A – D3. A + B + C 7. A – C4. A + C 8. D – B

Components of a VectorAny vector can be broken down into two components – Horizontal and Vertical

Any vector can be drawn as the sum of two other vectors drawn at right angles to each other. The two vectors are called components of the first vector.

Vector A = 4 cm north

Vector B = 3 cm east

Vector C = 5 cm bearing 37o

Draw a vector diagram to show that:

A + B = C• Vector A is the vertical component

of Vector C• Vector B is the horizontal

component of Vector C

1. Complete Activity 8A

2. Worksheets (pages 37 ~ 39)

3. Homework Booklet Sheet #1

Finish by Friday