1. Honors Physics 19 Oct 2009 Today and tomorrow: Virtual Projectile lab This is a mandatory lab assignment! Please turn in your free-fall graphical analysis lab work if you haven’t already!

2. Honors Physics 20 Oct 2009 Complete Virtual Projectile Labs – Turn in today if finished – Complete for homework and turn in tomorrow if you need more time. – Tomorrow: Projectile challenge – can you predict where your projectile will land using equations of motion?

3. Honors Physics 21 Oct 2009 Today: Projectile challenge – can you predict where a projectile will land? TOOLS d x = v x t (from EQ 2) d y = ½ gt 2 (from EQ 3) Timer, Board, Ball, Cup, Meter Stick

4. Idea behind the lab Calculate the distance that a projectile travels knowing the velocity of launch and the height Solve the y equation for t Roll a ball using a ramp to determine its launch velocity Plug this t into the x equation to solve for the x distance Put a cup this distance away from the edge of the table and try to catch it.

5. Honors Physics 22 Oct 2009 Today: More on vector analysis – and using trigonometry Homework: Practice B problems 1-4 on page 92

6. More on vectors Vector quantities have magnitude and direction – they are sometimes indicated by little arrows above the variable Addition of two vectors is NOT the same as adding scalar terms. You must use graphical or trigonometric methods (if you take a linear algebra course in college, you’ll learn another way to add vectors using matrices)

7. Vectors continued Adding two or more vectors gives you a “resultant,” so we say things like, “we resolve these vectors,” and so forth. Vectors can be moved for analysis, as long as they aren’t “turned” Vectors can be added in any order, but always “tip to tail.” You can multiply a vector times a scalar, getting a new vector

8. Rules for right triangles a 2 + b 2 = c 2 where c is the hypotenuse of a right triangle, and a and b are the short sides Sohcahtoa  – sin θ = opposite/hypotenuse – cos θ = adjacent/hypotenuse – tan θ = opposite/adjacent

9. Using trig - examples A plane flies north at 100 m/s while a wind blows to the east at 30 m/s. What are the resulting speed and direction of the plane? A cannon ball is fired at a speed of 100 m/s at an angle of 30 degrees with respect to the horizon. What are the x and y components of velocity

10. Honor Physics 23 Oct 2009 First – Homework check & warm-up An arrow is fired at a speed of 40 m/s at an angle of 20 degrees above the horizon. What are the initial x and y components of velocity? Together: How high does it go? How far does it go? What if you fired it from a 30 m high cliff?