1. Physics 1 – Oct 2, 2018 Get out Page 1-2 of IB 1.3
Worksheet for Hmk Check
P3 Challenge – Do Now (on slips of paper today)
What are the components of A = 65 m/s at 120o ?
What is -2A?

2. Objectives and Agenda IB 1.3 Vectors Agenda for IB 1.3 Vectors
Vectors in 2D analytically
Agenda for IB 1.3 Vectors
Homework Review
From Components to Magnitude and direction
Adding vectors analytically

3. Vector Components Complete the last 3 Problems on p2 now.
You can reverse the process by applying the Pythagorean Theorem and the definition of tangent.
Note that anytime you take the inverse tangent, there are two possible answers. The one your calculator tells you and one 180 opposite that angle. (from math class)
If Ax is negative, use the +180 version. (The sign of Ay is irrelevant.)
Complete the last 3
Problems on p2 now.

4. Sample Addition problem
A pack of four Arctic wolves are exerting four different forces upon the carcass of a 500 kg dead polar bear. Wolf one is pulling on the bear with a force of 20 Newtons (N) due north. Wolf two is pulling on the bear with a force of 30 N, 30 degrees north of west. Wolf three is pulling on the bear with a force of 25 N due west, and wolf four is pulling on the bear with a force of 35 N, 10 degrees west of south. Determine the net force acting upon the polar bear and the direction of that force measured north of east.

5. Adding Vectors Analytically
Add A = 4.0 N at 30 and B = 8.0 N at 135o analytically
1) Resolve all vectors into x and y components (Ax = A cos θ, Ay = A sin θ)
2) Add all x components to find resultant x component, Rx (use a table)
3) Add all y components to find resultant y component, Ry
4) Convert resultant components into magnitude and direction.
𝑹 𝒙 𝟐 + 𝑹 𝒚 𝟐 and 𝒕𝒂𝒏 −𝟏 ( 𝑹 𝒚 𝑹 𝒙 ) , (add 180o if Rx is negative.)
Usually best to organize this information in a table X Y A Ax Ay B Bx By R Rx Ry

6. Sample Addition problem
A pack of four Arctic wolves are exerting four different forces upon the carcass of a 500 kg dead polar bear. Wolf one is pulling on the bear with a force of 20 Newtons (N) due north. Wolf two is pulling on the bear with a force of 30 N, 30 degrees north of west. Wolf three is pulling on the bear with a force of 25 N due west, and wolf four is pulling on the bear with a force of 35 N, 10 degrees west of south. Determine the net force acting upon the polar bear and the direction of that force measured north of east.
Add analytically.

7. Exit Slip - Assignment
Add 15 m/s at 30 and 45 m/s at 240 graphically. Estimate the resultant.
Then add these two vectors analytically.
What’s Due? (Pending assignments to complete.)
IB 1.3 Vectors and Scalars Worksheet p3-4
What’s Next? (How to prepare for the next day)
Vector components dart lab on Thursday