Felix Varela Senior High
Physics
Buggy Lab: Constant Velocity
I. Objective: To determine a mathematical and graphical relationship between distance and time for a car traveling at constant speed.
II. Pre-Lab Activity:
1) Discuss factors that can change the motion of the car
2) Allow the students to see the vehicle and how it moves and discuss which items are quantifiable (measurable).
3) Discuss dependent and independent variables:
a) Explain why it is more useful to make time the independent variable (slope of a line describes velocity).
III. *Procedures:
Students should choose a method for collecting data. They should perform at least 10 (ten) trials.
*Note: If time is going to be the independent variable, then time intervals should be established, ie: position from the point of reference should be measured after 3 seconds, and every 3 s thereafter. It may be easier to measure the time at specific distances, ie: mark ten equidistant spots on the floor and measure the time it takes for the car to reach each point from the reference point.
IV. Observations:
1) Focus on the position vs. time relationship.
2) Discuss displacement.
3) Analyze graphs following method previously learned, interpret graph mathematically.
4) Discuss the meaning of the slope of the x vs. t graph (constant velocity).
5) Discuss the 5% rule-of-thumb and its relation to the y-intercept.
6) Discuss the meaning of “the area under the curve” for the velocity vs. time graph.
V. Unit II Modeling Objectives:
1) Determine average velocity using:
a) Slope of v vs. t graph.
b) Using equation v = (xf - xi)/(tf – ti)
2) Determine displacement using:
a) Area under v vs. t graph
b) Using equation (xf - xi) = vt
3) Given an x vs. t graph:
a) Describe the motion of the object (Reference frame, direction of motion, velocity)
b) Draw the corresponding v vs. t graph
c) Determine average velocity of the object
d) Write a mathematical model that describes the motion
4) Given a v vs. t graph:
a) Describe the motion of the object (direction and magnitude)Draw the corresponding x vs. t graph
b) Determine the displacement of the object
c) Write a mathematical model to describe motion
Unit II: Buggy Lab - S