Monday, September 23, 2013 H Physics Warm Up Find the a and Δx for the velocity vs time graph Standards: 1a Students know how to solve problems that involve constant speed and average speed. Learning Objective: SWBAT understand their mistakes from the last exam and rework the problems. Agenda: 1.Warm Up 2.Correct HW 3.Take Quiz P.2 4.Go over Test 5.Begin Redoing Test Questions Homework Redo Incorrect Test Questions Quiz Friday Make up Quiz Today After School Test Retake option available until Oct. 4th v(m/s) t(s)

Tuesday, September 24, 2013 H Physics Warm Up If a golf ball starts with a speed of 2.0 m/s and slows at a constant rate of 0.50 m/s 2, what is its velocity after 2.0 s? Standards: 1a Students know how to solve problems that involve constant speed and average speed. Learning Objective: SWBAT read and understand and interpret information presented graphically Agenda: 1.Warm Up 2.Review HW P.4 3.Correct Quiz P.2 4.Review Test P.2 Homework Quiz Friday Redo Inccorect Test Problems P.2 Graphing Worksheet P.4

Wednesday, September 25, 2013 H Physics Warm Up P.4 Draw a x vs t graph of an object that 1.accelerates + 2.Then stops abruptly 3.Then rolls forward slowly with a constant v Come up with a scenario that could describe this motion. Standards: Standards: 1a Students know how to solve problems that involve constant speed and average speed. Learning Objective: SWBAT read and understand and interpret information presented graphically Agenda: 1.Warm Up 2.P.2 Graphing Notes 3.P.2 Graphing Practice 4.P.4 Interpreting Graphs Problem 5.P.4 Motion Equations 6.Motion Equations Practice Homework Quiz Friday P.2 Finish Kinematics Graphs P.4 Solve acceleration problems P.2 A ball on a ramp starts from rest and speeds up to 20cm/s in 0.75s. What is the acceleration?

Thursday, September 26, 2013 H Physics Standards: Standards: 1a Students know how to solve problems that involve constant speed and average speed. Learning Objective: SWBAT Agenda: 1.Warm Up 2.Correct HW 3.P.2 Analyzing Graphs 4.P.4 Practice Solving Constant Acceleration Problems Homework Study for Quiz P.2 Graphing P.4 Acceleration Warm Up P.2 Draw a x vs t graph of an object that 1.accelerates + 2.Then stops abruptly 3.Then rolls forward slowly with a constant v Come up with a scenario that could describe this motion. P.4 Find the initial velocity of a train that accelerates at 4m/s 2 for 10 seconds and reaches a top speed of 28 m/s?

Friday, September 27, 2013 H Physics Standards: Standards: 1a Students know how to solve problems that involve constant speed and average speed. Learning Objective: SWBAT score at least 80% on Quiz 4 Agenda: 1.Warm Up 2.Review Homework 3.Take Quiz 4.Practice with eqns of motion Homework Extra Credit scenario drawing due Monday Quiz Retake Monday After School Last week to do test retake after School: Last days=Monday&Wednesday Warm Up P.4 How far did a dune buggy travel to get to the first set of dunes if it accelerated from its 40km/hr speed on the highway at a rate of 5km/hr 2 for 12seconds? P.2 What is the area under the v vs t graph equal to? and What does the slope of the v vs t graph equal to?

Analyzing Graphs In Physics there are three main purposes for drawing a graphical representation of motion. 2. To find its slope. These are the main reasons to make a graph in physics. There isn’t very much more information a graph can provide you, so if you are EVER going to make a graph, you will need to find one or all of these three things, else it is pointless. 3. To find the area under the curve. Area of a triangle=(base*height)/2 Area of a rectangle=Length*Width 1. To find its equation.y=mx+b, or another equation

Displacement vs. Time Graph x(m) t(s) Find the velocity from 0 to 4 s. 2. Find the velocity from 4 to 8 s. 3. Find the velocity from 8 to 10s. 4. What is the equation of the line segment that begins at 4 s and ends at 8 s 5. What is the area under the curve from 0s to 4s? Below is the motion of a radio controlled car

Velocity vs. Time Graph v(m/s) t(s) What is the speed of the car at 4s? 2.Find the equation of the line segment that goes from 6s to 10s. 3.Find the acceleration from 4 to 6 s. 4. Find the acceleration from 6 to 10s. 5.Find the displacement from 4s to 6s. 6.Find the displacement from 0 to 4 s This shows the change in motion of a radio controlled car.

Symbols, units and equations Study Guide --distance (d), displacement (Δx) units: meters (m) --speed (v s ), velocity (v) units: meters per second (m/s, km/hr) --acceleration (a) units: meters per second squared (m/s 2,km/hr 2 ) --time (t or Δt) units: seconds Equations:,

Relationship Between x vs t, v vs t and a vs t graphs Displacement vs. time graphs 1.Situation 1 i) the object is not moving ii) the object’s velocity is 0 iii) the object’s acceleration is 0 2.Situation 2 i) the object is moving ii) the object’s velocity is constant iii) the object’s acceleration is 0 3.Situation 3 i) the object is moving ii) the object’s velocity is changing iii) the object’s acceleration is constant Δx Δt Δx Δt Δx Δt Δx Δt Δx Δt

Using an x vs t graph to create a v vs t graph t(s)x(m) Take 3 minutes and sketch a graph from the adjacent table. 2. To use this position vs time graph that you drew to find a velocity vs. time graph, first find the slope of each section of the graph 3. Make a table of points, velocity vs time. t(s) x(m) v(m/s) t(s)

Practice Analyzing Graphs H 1. For graph 1 find the velocity from 0 to 9 hr, 12-18hr, and 21-27hr. 2. For graph 2 find the acceleration from 0 to 6hr, 6-8hr, 8-12hr, hr, and 16-20s and the displacement from 8-12s *3. For graph 3, use your v vs t graph to find the a vs. t graph and the x vs t graph t(s)v(m/s)

Identifying the motion from graphs. Four cars racing on a straight line track had motion described by each of the graphs below. Make a rough sketch of the race that shows the start and the final results. Each car is timed over equal time periods. In other words each graph ends at the same time. Δx(m) t(s) x(m) t(s) x(m) t(s) A B x(m) t(s) C D

More on Accelerated Motion Right now we useand when we solve problems with accelerating objects. Now we have some new equations. One will make solving some acceleration problems easier. One will allow us to solve a bigger variety of problems Specifically we will be able to solve problems involving falling objects and a larger variety of problems where objects are slowing down and speeding up.

In class practice A car traveling at 91.0 km/h approaches the turnoff for a restaurant 30.0 m ahead. If the driver slams on the brakes with an acceleration of m/s 2, (A) how long will it take for the car to stop? (B) What will be the car’s stopping distance. Write down the Givens: 2 minutes Draw the Diagram 3 minutes Choose the equation 1 minute Solve the problem 3 minutes.

Constant Acceleration Practice H 1.Which formula would you use to solve the following pr problems? Explain why. : 1.Solve problems a & b. 2.Find the uniform acceleration that causes a car’s velocity to change from 32 m/s to 96 m/s in an 8.0s period. 3.A car with an initial velocity of 22 m/s is accelerated uniformly at the rate of 1.6 m/s 2 for 6.8s. What is its final velocity? 4.A child throws a ball down a hill at 5m/s and rolls down the hill with a constant acceleration of 2.0 m/s 2. If takes the ball 4 s for the ball to run into a wall at the bottom of a hill, how far did it roll before it hit the wall? 5.A race car can be slowed with a constant acceleration of -11m/s 2. If the car is going 55m/s before it slows. How long does it take before the car stops? 6.*A dragster starting from rest accelerates at 49m/s 2. How fast is it going when it has traveled 325m? vfvf 0 m/s vivi 40 m/s Δxnot given a-3 m/s 2 t? vfvf not given vivi 20 m/s Δx? a-3 m/s 2 t4.5s a b

Constant Acceleration #2 H 1.A car accelerates from rest at a rate of 2.0 m/s 2 for 22 seconds. How far does the car travel while accelerating? 2.A car accelerates from rest at 1.0 m/s 2 and covers a distance of m. How long did it take? 3.A boat accelerates at 0.5 m/s 2 until it reaches 35 m/s. If its initial velocity was 5.0 m/s, how long did it take? 4.A car covers a distance of m in 20.0 s. What was the car’s acceleration? 5.What was a motorcycle’s acceleration that went from 0 to 40 m/s is 5.2 seconds? 6.*A plane speeds up from rest to 270 m/s in 40 seconds How far did the plane travel? Hint: use both motion equations.

Constant Velocity & Acceleration C: Lets make our own word problems: To create a word problem answer the following questions. 1.Which equation do you want this problem employ (use)? Ex. 2.Which letter in the equation do you want to make your unknown? Ex. t=? 3. You get to make up numbers for all other letters in the equation. Ex. Δx=0.7m, a=4m/s 2, 4. What object do you want to feature in your problem? Ex. baseball. 5. Now construct a setting or a scene for the motion to happen in. Ex. During a game a pitcher winds up and accelerates a baseball. If the pitcher accelerates the ball during his 0.6 meter long windup at 4m/s 2, how long did the pitchers windup take? 6. Now you’re done. Solve it! Find the Givens and Draw a diagram For Homework Make 2 Word problems and solve them. Make 1 for each equation.

Honors Acceleration Practice C: Lets make our own word problems: To create a word problem answer the following questions. 2. Which equation do you want this problem employ (use)? Ex. 3. Which letter in the equation do you want to make your unknown. Ex. t=? 4. You get to make up numbers for all other letters in the equation. Ex. Δx=0.7m, a=4m/s 2, 1. What object do you want to feature in your problem? Ex. baseball. 5. Now construct a setting or a scene for the motion to happen in. Ex. During a game a pitcher winds up and accelerates a baseball. If the pitcher accelerates the ball during his 0.6 meter long windup at 4m/s 2, how long did the pitchers windup take? 6. Now you’re done. Solve it!. Write Your Givens. Draw Your Diagram. For Homework Make 2 Word problems and solve them. Make 1 for each equation.