218 Adv Alg Bell Ringer Solve for x
2/18 Adv. Alg. Bell Ringer Solve for x by factoring: X 2 + x – 12 = 0 X 2 – 6 x = -8 Homework: Review Packet!
2/18 News and Notes • Perfection: 8 th • Bell Ringers in? • Review Packet this weekend, Review Tuesday, Test Wednesday • Golden Tix
You’ll either love me or hate me… How does the calculator do this stuff? Identify the values for a, b, and c: X 2 – 6 x = -8 +8 +8 X 2 – 6 x + 8 = 0 A = 1, b = -6, c = 8
A = 1, B = -6, C = 8 • • • Push PRGM Scroll to “QUADFORM” Hit Enter ‘a’ value Hit Enter Now b Hit Enter Now c Hit Enter…SOLUTIONS!!!!
Why did I show you this now? • Because not every calculator does this, and you need to understand the underlying math. • You need to appreciate technology • Now you can focus solely on the Physics applications you’re about to discover.
Physics Exploration • You’re playing Angry Birds on your sweet new i. Phone and get curious about the maximum height, distance, and time the bird is in the air before it hits the ground again. You remember this formula from Physics class (maybe? )
Key Information Box: T = Time (in seconds) Our unknown variable in most cases G = Gravity 4. 9 if unit is meters, 16 if unit is feet V 0 = Initial velocity either m/s or ft/s h 0 = Initial Height of object feet or meters
If you launch a bird at an initial velocity of 10 m/s from the ground, how long will it take until the bird hits the ground again? What do you know? • v 0= 10 m/s • g = 4. 9 (because we’re in meters) • h 0= 0 because FROM GROUND
If you launch a bird at an initial velocity of 10 m/s from the ground, how long will it take until the bird hits the ground again? What do you WANT to know? • time until s(t) = 0 again.
• A = -4. 9 • B = 10 • C=0 • Answer: Hits ground again 2. 04 sec. after launch. • Key Question: Why not the negative?
New Question If you launch a bird at an initial velocity of 10 m/s from the ground, what is the maximum height the bird will reach? When will the bird reach this height? What do we want to know? • VERTEX!
• Graph it and find the vertex. • Max height is y-coordinate, time is xcoordinate. • In a sentence: “Bird reaches maximum height of 5. 16 meters after 1. 06 seconds.
Share your whiteboard with your partner and answer the following questions in 45 seconds. An object in launched directly upward at 64 feet per second (ft/s) from a platform 80 feet high. • Question 1: What is the initial velocity (v 0)? • Question 2: What is the initial height (h 0)? • Question 3: What is the value for g? • Question 4: What’s our equation? • Question 5: What are the values for a, b, and c? • Question 6: How long will it take before the object hits the ground? • Question 7: What is the maximum height, and after how many seconds will the object reach that height?
Bonus! • After how many seconds will the bird be be 210 feet off the ground?
Now… Practice!
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