Kinematics Stuff moving stuff The Equations All you

Kinematics (Stuff moving) (stuff)

The Equations! All you get on AP Equations Sheet Don’t forget these definitions!

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. 17 m Unknown: aavg=? ? Principle: Kinematics(where to look for eq’n) Picture: Equation: Simplify/Solve/Substitute zero

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.

v(m/s) Aircraft Catapult(v) 50 5 time(s)

a(m/s 2) Aircraft Catapult(a) 20 5 time(s)

x(m) Aircraft Catapult(x) 300 200 100 5 time(s)

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Freefall • Same kinematics equations… • Just constant acceleration of a=g=9. 8 m/s 2 • 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: v 0=-3. 0, a=5, Dt=4, Dx=? • Try a “spike” (as in football player’s touchdown celebration) – xf=-5. 0, x 0=2. 0, v 0=-1. 0, a=-9. 8, Dt=?

The Equations! Don’t forget definitions