Lab: Acceleration Question: How is the speed of the car changing? Objectives: 1. Determine the rate of acceleration through a calculation. 2. Determine the rate of acceleration using a graph. Background Information is how an object’s Acceleration VELOCITY changes over a period of time. Hypothesis we graph Velocity vs. Time for If a toy car, then we will be able to calculate _____________. Lab: Acceleration (continued) Procedure: 1. Roll the car down the ramp and record the three times: Time A (A light lit), Time B (B light lit), and Time A to B (Both lights lit) 2. Calculate the speeds at A and B speed A= 5cm/Time A speed B = 5cm/Time B 3. Calculate the Acceleration (Speed B – Speed A)/Time A to B 4. Move the photogates to a new position for trial 2 and repeat steps 1-3. Graph Time is the independent variable, so Time (in seconds) goes on the x axis. Speed is the dependent variable, so Speed (cm/s) goes on the y axis. Your graph should have 4 points: For trial 1: (time A, speed A) and (time B, Speed B) For trial 2: (time A, speed A) and (time B, speed B) Data Trial 1 Trial 2 Time A Time B Time A to B Speed A Speed B Acceleration Analysis 1. Is your graph a straight line or a curve? 2. What does the y-intercept of your graph represent? 3. Does the car accelerate as it moves down the ramp? Justify your answer. Analysis continued 4. Calculate the acceleration of the car by calculating the slope of the line. 5. Is the acceleration of the car changing as it moves down the ramp? Explain. Analysis continued 6. When the car is speeding up, is tis acceleration positive or negative? Support your answer with your data. Velocity vs. Time 2 Velocity (m/s) 1.5 1 0.5 0 0 2 4 6 Time (s) 7. A car traveling 1.6 m/s eventually encounters a ramp (negligible friction). Calculate the speed of the cart at t = 2.5 s. Velocity vs. Time 2 Velocity (m/s) 1.5 1 0.5 0 0 2 4 6 Time (s) 8. Calculate the distance traveled by the cart from t = 2.0 s to t= 3.5 s. Reflection and Summary In the first paragraph, summarize the purpose and results of the lab. In the second paragraph, tell me at least 5 things that you learned about speed and acceleration.