Go, Go, Go Lab

1
Go, Go, Go Lab

• Lettuce and Tomato were in a race, what happened?

The lettuce was a head and the tomato was trying
to ketchup.
2
Purpose

• To observe an object with constant velocity and
  to plot a graph for that represents that objects
  motion.

3
Nuts and bolts

• Timing 3 different cars
• Many different distances
• Calculating speed (velocity)

4
Hypothesis

• Hypothesis If the car is moving at a constant
  velocity then

5
Hypothesis

• Hypothesis If the car is moving at a constant
  velocity then the graph will be a straight line
  because the car will cover Equal Distance in an
  Equal time.

6
Variables

• Independent variable
• What are we trying to test?
• How the distance affects the speed
• Dependent variable
• What are we trying to measure
• Time of each car (speed)

7
Materials

• Three different constant motion cars
• 2 small and 1 large
• Painters tape
• Stop watch

8
Roles (groups of 3)

• Recorder
• Timer- Start the watch when the car crosses the
  first line and report the time to the recorder
  after every go
• Car technician-starts the car, retrieves the car
  and repairs car.

9
Procedures

• Find a straight stretch of tiles in the room and
  place 7 marks (one mark every 60 cm) with a
  little blue tape
• Release the car at least 2 tiles behind the first
  mark
• Start the time when the car reaches the first
  mark.
• Record the time when the car reaches each mark.
• Let the stop watch keep rolling until the end of
  the track.
• Repeat two more times and two more cars
• Three trials each car
• Three cars total
• Each car has its own data table (three data
  tables)

10
Practice as a class
Start Time
Release car
Time ? d 2 feet
Time 0 d 0 feet
Time ? d 4 feet
Time ? d 6 feet
Time ? d 8 feet
Time ? d 10 feet
Keep the clock rolling until the end
11
Data Table
Add across and devide by 3 to find average
12
GraphDraw a line of best fit.
Distance cm
Time (s)
13
Analysis

• Define constant velocity
• Did all of the cars experience constant velocity?
  Explain how you know.
• How is constant velocity different than
  instantaneous velocity? (Think speedometer vs.
  trip to the coast) 
• Make a graph of your three cars (distance on the
  Y axis, and time on the x axis). Use a different
  color for each car (indicate in key on graph).
  Use a straight edge to connect the data points. 
• Which car had the highest constant velocity?
  (describe the steepness of the line)
• Which car had the lowest constant velocity?
  (Describe the steepness of the line)
• What errors could/may have occurred in the lab
  that might have stopped your cars from having
  constant velocity?

14
Analysis

• 9. Add a line to your graph that represents a
  faster car, label it appropriately
• 10. Add a line to your graph that represents a
  slower car, label it appropriately
• 11. Suppose the cars battery ran out during the
  run, so that the car slowly came to a stop. Add
  a line to your graph that represents a car
  slowing down to a stop.