Kinematics

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## Kinematics

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**Kinematics**(Stuff moving) (stuff)**The Equations!**Don’t forget these definitions! All you get on AP Equations Sheet**The area of a velocity “curve” is displacement!**v Avg velocity area t**Kinematics Examples**• Drag race • Avg velocity given time and disp • Avg acceleration given final v and disp • Motion Graphing • Aircraft Catapult • Draw position and acceleration given velocity**Drag Race**1. A car travels 402 .34 meters in 11.963 sec. What is its average velocity? 2. The same car reached 40.73 m/s at the end of the first 201.17 meters. What was its average acceleration?**Drag Race #1**Given: Dx= 402 .34 meters in Dt=11.963 sec. Unknown: vavg=?? Principle: Kinematics(where to look for eq’n) Picture: Equation: Simplify/Solve/Substitute**Drag Race #2**Given: vf= 40.73 m/s in Dx=201.17m Unknown: aavg=?? Principle: Kinematics(where to look for eq’n) Picture: zero Equation: Simplify/Solve/Substitute**Aircraft catapult**• Navy aircraft are launched from the decks of aircraft carriers with a steam powered catapult. The graph shows the velocity of the aircraft as a function of time. Analyze the graph and draw corresponding position and acceleration graphs.**Aircraft Catapult(v)**v(m/s) 50 time(s) 5**Aircraft Catapult(a)**a(m/s2) 20 time(s) 5**Aircraft Catapult(x)**x(m) 300 200 100 time(s) 5**Freefall**• Same kinematics equations… • Just constant acceleration of a=g=9.8 m/s2 • toward earth. Do yourself a favor and call down negative.**Freefall Example**• 2) A ball is given an upward velocity of 5.0 m/s, what is the maximum height it will reach? • 3) How long does it take to reach this max height?**Freefall Example**• 5) A ball is thrown upward with a velocity of 4.0 m/s. How fast is it going when it hits the ground, 10 meters below where it was thrown from?**Freefall Cases**• Downy • Dropping or “spiking” • Uppy • Toss up • Uppy – downy • Toss up off a ledge, object lands lower than the ledge Establish your coordinate system and be consistent with signs.**Wrap up**• Givens • Unknowns • P&P • E • Time or none given • S & S & S**More examples**• More example problems • Try: v0=-3.0, a=5, Dt=4, Dx=? • Try a “spike” (as in football player’s touchdown celebration) • xf=-5.0, x0=2.0, v0=-1.0, a=-9.8, Dt=?**The Equations!**Don’t forget definitions