Constant Acceleration Lab恒定加速实验室.doc

Constant Acceleration LabIntroductionIn this lab you will compare two objects that are undergoing constant acceleration.Objectives Collect position, velocity, and acceleration data as a ball travels straight up and down and for a fan cart moving away and back. Analyze the position vs. time, velocity vs. time, and acceleration vs. time graphs. Determine the best fit equations for the position vs. time and velocity vs. time graphs. Determine the mean acceleration from the acceleration vs. time graph.MaterialscomputerVernier Motion DetectorVernier computer interfacevolleyball or basketballLogger Prowire basketHorizontal rampFan CartProcedurePart 1 : Ball Toss1.Connect the Vernier Motion Detector to the DIG/SONIC1 channel of the interface.2.Place the Motion Detector on the floor and protect it by placing a wire basket over it. Make sure that the motion detector is placed away from the table as far as possible so to reduce any interference with the coned shaped ultrasonic beam.3.Open the file “06 Ball Toss” from the Physics with Vernier folder found in Vernier Software Logger Pro. 4.In this step, you will toss the ball straight upward above the Motion Detector and let it fall back toward the Motion Detector. This step may require some practice. Hold the ball directly above and about 0.5 m from the Motion Detector. Click to begin data collection. You will notice a clicking sound from the Motion Detector. Wait one second, then toss the ball straight upward. Be sure to move your hands out of the way after you release it. A toss of 0.5 m above the Motion Detector works well. You will get best results if you catch and hold the ball when it is about 0.5m above the Motion Detector.5.Examine the position vs. time graph. Repeat Step 4 if your position vs. time graph does not show an area of smoothly changing position. Check with Mr. Fawcett if you are not sure whether you need to repeat the data collection. 6. For each graph press the auto-scale button (A) on the top menu bar to resize. You can also put your mouse pointer over the axis and when a curly arrow appears click and drag to resize, or click on the highest value on each axis and enter your own range.7. Title your graphs “ball toss” and put your group members names on them before printing.Part 2: Fan Cart1. Set the motion detector on the end of a horizontal ramp positioned on blocks to raise it above the computers. Angle the head of the motion detector so that it will pick up the full motion of the cart down the ramp. You might have to play around with this at first.2. Position the cart at least 0.5 m from the motion detector and turn it on with the low setting and the fan pushing the cart towards you. Do not leave the cart running for long or you will wear the batteries down!3. Click to begin data collection. Push the cart away from you so that the cart moves down the ramp and then comes back to you under its own power. Be careful not to push it too hard!. Turn the fan off after it comes back to you. 4. For each graph press the auto-scale button (A) on the top menu bar to resize. You can also put your mouse pointer over the axis and when a curly arrow appears click and drag to resize, or click on the highest value on each axis and enter your own range. 5. Title your graphs “Fan Cart” and put your group members names on them before printing. Analysis Questions1. In what way(s) is the fan cart motion similar to the ball toss motion?2. In what ways(s) is the fan cart motion different to the ball toss motion?3. Label on the ball toss v-t graph the point where the ball has reached maximum height. What is its speed and acceleration at this point?4. Label on the fan cart v-t graph the point where the cart has traveled the furthest distance from the motion detector. What is it speed and acceleration at this point?5. When the balls or carts velocity is zero, is its acceleration zero? Explain why or why not!6. Sometimes the cart or balls velocity is positive and sometimes it is negative but the cart or balls acceleration is always negative and constant. Explain why the cart or balls acceleration isnt changing unlike the velocity.7. Could you produce the same shaped graphs by driving in a car? Explain!Constant Acceleration LabScoring RubricName(s) _ Class_Part 1: Ball Toss1. Three motion graphs _ 5 ptsPart 2: Fan Cart2. Three motion graphs _ 5 ptsAnalysis Questions3. Explained how the fan carts motion is similar to the ball toss motion _ 2 pts4. Explained how the fan carts motion is different to the ball toss motion _ 2 pts5. Labeled ball toss v-t graph at highest point Described the speed and acceleration at this point _ 6 pts6. Labeled fan cart v-t graph at furthest point Described the speed and accele