Scalar Quantity

Vector Quantity

Quantity having magnitude only

Quantity having magnitude and direction

Mass – 5 kgTime – 6 sDistance – 50 m

Velocity – 5 m/s, NorthForce – 10 N, 300 S of WAcceleration – 1.5 m/s2 , NE

Scalar AdditionAddition of arithmetic numbers

Mass – 5kg + 7kg = 12 kg

Time – 6 s + 4 s = 10 s

Distance – 50 m + 100 m = 150 m

Vector AdditionAddition of arithmetic numbers with

consideration to the directions1. The vectors have the same direction

- just add the magnitude and copy the direction

5m/s, N + 5 m/s, N = 10 m/s, N15 N, West + 25 N, West = 40 N, West

2. The vectors have opposite direction

- just subtract the magnitude and copy the direction of the vector with higher magnitude

5m/s, N + 4 m/s, S = 1 m/s, N15 N, SW + 25 N, NE = 10 N, NE

Vector Addition3. The vectors have perpendicular direction

- use Pythagorean Theorem (a2 +b2 = c2)

3 m/s, N + 4 m/s, E = ___________

22 /4)/3( smsmR

smR /5

EofN

sm

sm

0

1

87.36

75.0tan

/4

/3tan

EofNsmR 087.36,/5

Guided ExercisesAdd the following Quantities

1. 5.2 kg + 8.6 kg = _____ kg2. 9 m/s + 3 km/h = _____ km/h3. 6.9 km, N + 3.5 km, N = _____4. 15 m/s, S + 32 m/s, N = _____5. 5 m, 300 N of E + 3 m, 300 S of W =6. 7.5 m, N + 3 m, E = _____7. 5 m, NE + 5 m, SW = _______8. 10 m, 300 S of W + 5 m, 600 N of E =

SeatworkAdd the following Quantities

1. 57.84 kg + 81.65 kg = _____ kg2. 2.75 km + 6576.65 cm = _____ cm3. 90 m/s + 561 km/h = _____ km/h4. 65.78 km, N + 39.63 km, N = _____5. 159.62 m/s, S + 329 m/s, N = _____6. 5 m, 300 N of E + 3 m, 300 S of W = _____7. 6 m, NW + 3.75 m, SE = _____8. 6 m, N + 8 m, E = _____9. 3 m, SE + 3 m, SW = _______10. 5 m, 300 N of W + 10 m, 600 N of E =