Transcript crla slides
Teaching Physics to Non-Physicists CRLA Conference 2012 (Session 69) Presenters: William Wolfs, Mentor Tutor Chyna Miller, Tutoring Coordinator University of Nevada Las Vegas, Academic Success Center Inside Outside Any Questions? It's 340 meters per second, Einstein! An F-18 fighter jet breaks the sound barrier STEM Degrees, 2007 Source: NSF Engineering Agricultural sciences Biological sciences Earth, atmospheric, and ocean sciences Chemistry Mathematics/st atistics Astronomy Physics Grades for Biology Students A 12% F or W 23% A7% B+ 3% D 4% B+ 13% C6% B6% C+ 4% C 20% Physics: The Least You Need To Know 1. ΣF = ma 2. x = ½at2 + v0t + x0 3. v = at + v0 4. v2 = v02 + 2ax 5. f = μN 6. ac = v2/r 7. p = mv 8. W = Fx = ΔE 9. FG = GMm/r2 10. FS = -kx 1. When something gets pushed on, its velocity changes. 2. The path of an object over time depends on its initial velocity and acceleration. 3. The velocity of an object over time depends on its initial velocity and its acceleration. 4. The velocity of an object after a distance depends on its initial velocity and its acceleration 5. The more of an object's weight a surface supports, the more friction between the object and surface. 6. If an object moves in a circle, it is always getting pulled toward the center of that circle. 7. The heavier something is and the faster its going, the more momentum it has. 8. If an object feels a net push over a distance, its energy changes. 9. Gravity between two objects depends on their mass and the distance between them. 10. Pull on a spring and it pulls back. What's wrong with Sisyphus? Isn't he pushing? But the rock isn't moving! 1. ΣF = ma Force Diagram B A: Sisyphus' burly arms. D C B: Boulder's immense weight C. Friction with the bumpy ground D. Normal Force A NO NET PUSH! 1. ΣF = ma 5. f = μN Boulder wins again, Sisyphus Where Does the Ball Go? 2. x = ½at2 + v0t + x0 3. v = at + v0 4. v2 = v02 + 2ax Why I Am Not A Golfer That tree moved! You all saw it! 2. x = ½at2 + v0t + x0 3. v = at + v0 X 4. v2 = v02 + 2ax If A Real Golfer Hit A Golf Ball A B B C A: Rising Velocity B: Constant Horizontal Velocity C: Falling Velocity 2. x = ½at2 + v0t + x0 3. v = at + v0 4. v2 = v02 + 2ax 6. ac = v2/r 9. FG = GMm/r2 Big Goat: 300 lbs,10mph Medium Goat: 200 lbs 15 mph Little Goat: 100 lbs 30 mph 7. p = mv The Mystery of Math You may not realize . . . . If x=y and p=q: If ax2 + bx + c = 0, then: x(p) = y(q) x+p = y+q x/p = y/q 10x = 10y C A θ B 1. 2. 3. 4. A2 + B2 = C2 Sinθ =A/C - A = (C)Sinθ Cosθ = B/C B = (C)Cosθ Tanθ = A/B Gravity on the Moon? The Earth is about 100 times more massive than the moon. It is also about 4 times larger in radius. Neil Armstrong prepares to jump 7 feet straight up One Method to Rule Them All ...... 1. 2. 3. 4. 5. Draw a picture. Label everything. Pick coordinates. Pick your physics. Do the math. That doesn’t seem so hard. Or evil. Draw a Picture! A: Sisyphus' burly arms. Label Everything! B: Boulder's immense weight B C. Friction with the bumpy ground D C D. Normal Force A Y X Pick Your Coordinates! B D Bx B C θ By Bx = Bsin(θ) By = Bcos(θ) θ A 1. ΣF = ma 2. x = ½at2 + v0t + x0 3. v = at + v0 4. v2 = v02 + 2ax 5. f = μN 6. ac = v2/r 7. p = mv 8. W = Fx = ΔE 9. FG = GMm/r2 10. FS = -kx We have a situation where we are worried about how hard something is being pushed, so we pick the law having to do with force! Pick Your Physics! Do the Math! Don’t be afraid. Those symbols don’t bite … well, they don’t eat much when they do. To Sum Up: 1. Emphasize the simplicity and sparsity of the physical and mathematical tools needed. 2. Emphasize the importance of intuition and creativity. 3. Emphasize the wide applicability of the five-step method. Thank you for joining us! William Wolfs, Mentor Tutor UNLV Academic Success Center [email protected] Chyna Miller, Tutoring Coordinator UNLV Academic Success Center [email protected]