Kinematics Terms and Questions What measures must be known to… Make a moving object catch a falling object? Program a yellow light for safe use?

(Your) Kinematics Questions (so far…) How fast…? How far…? How long…? Where…? When…?

(Your) Kinematics Questions (after editing) - - when? - - where is (was) object? - - how long does (did) motion take? - - how far does object move? - - how far (and which way) is object moved from start? - - how fast is object moving? - - how fast & which way is it moving?

Measurement Names -time - -duration - -position - -distance - -displacement - -speed - -velocity - -Which of these terms relates two other terms?

Kinematics Measures - (t) time - when -(x,y,z) position - where object is/was -(Dt) duration - how long does (did) motion take -(d) distance - how far object moves -(Dx)displacement - how far (and which way) object is moved from start - (S) speed - how fast is object moving -(v) velocity - how fast & which way its moving

Using word webs for vocabulary Word Webs mimic how your brain works Word Webs can be added to Word Webs take LESS time to write than traditional notes, because you write just what you need Ex: duration (see side board)

Live Problem Determine the jeep’s average speed. Write it as a word problem, NOT a lab report.

Formulas Dt = tf – to Dx = xf – xo S = d / Dt v = Dx / Dt

Time vs Duration What is the difference? What is the same? Which one must be computed if you use a traditional clock? How do you perform that computation

Distance vs Displacement What is the difference? What is the same? Which measurement matters to a football coach? Which one affects how tired a running back would be at the end of a play? Which one is 1600m when the “mile” is run at a track meet?

Speed and Velocity What is the difference? What is the same? What formulas are used? What do you call the value if the speed of the object isn’t constant?

Speed vs Velocity Example At a CB South track meet, Pat competes in the 1600m (4 laps of the 400m track). Pat completes the first lap of the race in 60.0 seconds, the second lap in 62.0 seconds, the third lap in 73.0 seconds, and the last lap in 65.0 seconds. Compute Pat’s average speed or average velocity (whichever has relevance in this problem). Now compute the answer in miles per hour.

POD Its 3rd and 7 in the last minute of the 4th quarter. Eagles 21, Native Americans 17. Washington is on the Eagles 25 yard line. RG3 takes the hike, and backs up to the 30, fires a pass right over the middle to the newly acquired Jackson. The pass is beautifully thrown, so that even a Physics teacher could catch it. After the catch, Jackson is hit so hard his eyes just about pop out and he is brought down at the 20 yard line. The entire play takes 3.50 seconds. Compute the displacement and average velocity for the play. Show all steps!

time, duration, position, distance, displacement, speed, velocity What is the mathematical relationship between ________ (__) and _______ (__) for the jeep (that moves slow and steady)? What are the best two kinematics measurements that will fit this question? time, duration, position, distance, displacement, speed, velocity

What is the mathematical relationship between… the displacement (m) and duration (s) for the jeep while it moves slow and steady? the displacement (m) and duration (s) for a lab cart that starts from rest and steadily speeds up? Use a Ticker Tape to determine the jeep’s position every tenth of a second for 1.5 seconds Determine the equation that relates position to time for the jeep (while it is in motion). Explain what the equation means. (what it tells you)

Steps to a mathematical relationship lab: Perform trials, recording data – be sure you know which is dependent and which is independent! Graph Data Determine equation of line or curve. Explain, illustrate relationship. Take a PLQ, or write a report. Or, write your own report during the lab, then the PLQ is open report!

What is the mathematical relationship between the displacement (m) and duration (s) for the jeep while it moves at a constant speed? -The (change of) position of the jeep is directly proportional to (the change of) time, as shown by the equation: x(t) = 0.443t -0.023 -This means that the jeep will change position twice as much in twice the change in time. -For example, if the jeep moved from the origin to position A by time t, then it would move to position 2A by time 2t. This is because the jeep moved with a constant …

What is the mathematical relationship between the displacement (m) and duration (s) for the cart that starts from rest and gains speed?

What is the mathematical relationship between the displacement (m) and duration (s) for the cart that starts from rest and gains speed? -The (change of) position of the cart is exponentially proportional to (the change of) time (with an exponent of 2), as shown by the equation: x(t) = 0.1182t2 + 0.1004t -0.00174 -This means that the cart will change position four times as much in twice the change in time (if it starts from rest). -For example, if the cart moved from the origin to position A by time t, then it would move to position 4A by time 2t. This is because the cart ….

Post Lab Questions: Which vehicle moved farther in 1.5 seconds? Which vehicle moved faster in the 1.5 seconds? What is the mathematical relationship between velocity (m/s) and time (s) for… The jeep? The cart?

What is the mathematical relationship between… Velocity (m/s) and time (s) for a cart , if it starts from rest at x=0.0m at t=0.0s and rolls down a hill?

How to Get velocity from an x-t graph: Hold cart 0.5m from the detector. From the Experiment menu, select zero. Click collect, release the cart about 1 second later. Does the graph look as though your car started from rest at t=0.0s? If not, re-do From the ANALYZE menu, select tangent. Position the cursor at no fewer than 10 times along the curved section. Record these times and velocity values neatly in a table on WB. In the Data Menu, select New Manual Column – make this column velocity in m/s. Enter data. Switch the name of the vertical axis to velocity. Shade the portion with the clear pattern. Analyze the new graph.

What is the mathematical relationship between… velocity (m/s) and time (s) for a cart , if it starts from rest at x=0.0m at t=0.0s and rolls down a hill? 3. Analyze your data on logger pro 4. Prepare your report for a post lab quiz

What is the mathematical relationship between the velocity (m/s) of a cart and time (s), if the cart started from rest at x=0.0m at t=0.0s and rolled down a hill?

What is the mathematical relationship between the velocity (m/s) of a cart and time (s), if the cart started from rest at x=0.0m at t=0.0s and rolled down a hill? The cart’s velocity is directly proportional to time, as shown by v(t) = 0.2354t + 0.1006 This means that if you wait twice as long, the cart will be going twice as fast. For example, If a child on a sled reaches a speed of 2m/s 5 seconds after starting down a hill, then the child will reach 4m/s by 10s.

More Post Lab Questions: What does the slope of an x-t graph tell you? What quadrant(s) does a v-t graph need to have? Why? Is the origin shown on a v-t graph? (How, or why not?) What does the slope of a v-t graph tell you? Can you determine position or displacement from a v-t graph? (How?)

Lecture: Equations of Constant Acceleration x(t) = 0.1182t2 + 0.1004t -0.00174 v(t) = 0.2354t + 0.1006

Lecture: Equations of Constant Acceleration xf - xo = vot + 1/2at2 vf = vo + at xf-xo = ½ (vo + vf)t vf2 = vo2 + 2a(xf-xo)

Symbols - Terms - Questions - - when? - - where is (was) object? - - how long does (did) motion take? - - how far does object move? - - how far (and which way) is object moved from start? - - how fast is object moving? - - how fast & which way is it moving? - - how quickly does the _______ change?

Terms – Definitions -time - -duration - -position - -distance - -displacement - -speed - -velocity - -acceleration - Which of these terms relates two other terms?

Kinematics Terms Organized by … time position duration distance displacement speed velocity acceleration

Terms and Equations -duration - -displacement - -speed (ave) - -velocity (ave) - -acceleration (ave)-

Do you KNOW the Terms? What’s happening if an object has: Constant position? Constant VELOCITY? Constant SPEED? Constant acceleration? Constant position is the same thing as zero: Constant velocity is the same thing as zero:

Do you KNOW the Terms? From a sketch of a position vs time graph OR a velocity vs time graph, you should be able to tell: The direction of motion (positive or negative) If speed is constant, increasing or decreasing Of those things, the only thing an acceleration graph tells is if the speed is constant or changing

What is the cause? Is there a cause of If so, what is the cause? position? velocity? acceleration? If so, what is the cause?

A NET Force The cause of acceleration The result of adding all the forces acting on an object A vector, and the acceleration it causes is in the same direction