Vectors 34 Vectors Vector A quantity which can

Vectors 3+4=?

Vectors Vector – A quantity which can be described by it’s magnitude and direction. Scalar – A quantity which can be described by it’s magnitude only. Magnitude – How big something is. Hint – You can point in the direction of a vector.

Vectors Examples of Vectors and Scalars Vectors Scalar Time (3 min) Temperature o (32 ) Displacement (4 ft North) Distance and Length (4 ft) Velocity (100 Km/hr South) Speed(100 Km/hr) Force (gravity downward) Weight (Newton Downward) Mass (5 Kg)

Vectors Drawing Vectors or “Graphing” Vectors An arrow is used to represent a vector. Arrowhead represents direction. Length represents magnitude. Bad Vector: 3 m

Vectors Adding scalar quantities Mass: 1 kg + 1 kg = 2 kg Time: 2 s + 4 s = 6 s Distance: 10 m + 5 m = 15 m Since we are not dealing with direction we simple add the quantities.

Vectors Adding vector quantities (Tip to Tail or Start to Finish) Unlike scalars, vectors have a direction and we cannot add them like we do with scalar quantities. Vector “A” Vector “B” Finish Start Vector “C”= Resultant = the addition of two of more vectors.

Why Does It Matter? 1) How much did the person walk? 3 m Distance = 3 m + 4 m = 7 m 4 m 2) How far is the person from its initial position? a 2 + b 2 = c 2 Displacement = 5 m 37 o E of N

Example: Find the resultant of 4. 3 m N and 8. 5 m E 1 cm = 1 m n n 8. 5 m n 4. 3 m 26 o 9. 6 m n n Resultant = 9. 6 m, 260 E of N Procedure: 1. Choose an appropriate scale so each vector is about 5 – 10 cm 2. Draw the vectors to scale 3. Draw and measure the resultant 4. Measure the angle from start to resultant