Monday, 9/30Unit 3: Two dimensional motion.Introduction to vectors

Monday, 9/30• On a sheet of paper respond to the

following:1. What does a pilot need to know

when they are flying from Dallas to Chicago?

2. What does a baseball player need to do in order to be safe (any base)?

3. What does a volleyball player need to do when serving a ball?

Where we’ve been We have studied motion going

horizontally and vertically. We have been able to describe an

objects motion using graphs, diagrams, words, and numbers.

Let’s review…

Important terms

Displacement•Distance is its magnitude•Has directionVelocity

• Speed is its magnitude• Has direction

Vector ExampleAn Airplane flies east at a velocity of 120 km/h. There is a 30 km/h tailwind. What is the total velocity of the plane?

Vector ExampleAn Airplane flies east at a velocity of 120 km/h. There is a 30 km/h headwind. What is the total velocity of the plane?

How would you approach this problem?A boy walks 9.0 km north and then 6.5 km east?

Where we’re going…2D MotionUse vectors to describe motion of an object that is traveling in both the x and y direction.Vector components

Two or more vectors acting on the same point.

Resultant One vector having the same effect as the

combined components.

Visual of new termsResultant

X Component

Y Component

Apples and Oranges

• velocity + velocityacceleration + accelerationdisplacement + displacement

OK

• velocity + acceleration: NO!

• When adding vectors they must represent the same motion

Adding Vectors – head to tail method1. Start with a bold dot2. Draw the longest vector first3. Draw the next vector head to tail4. Draw the resultant from the big dot to

the last arrow head.5. Measure the resultant (graphically,

measured, or calculated).

Adding vectors

A

C B

A + B = C

A

B

Given the same vector components will the magnitude of the resultant change?

How would you approach this problem now?A boy walks 9.0 km north and then 6.5 km east?