Motion
_
Skills Lab
Inclined to Roll
Problem
How does the height (steepness) of a ramp affect how fast an object moves
across the floor?
Skills Focus
measuring, calculating, graphing
Materials
golf ball Meter stick
Flat board approx. 88.5 cm long Masking tape
Supports to prop up board (books) 2 stop watches
Procedure
1. EACH OF YOU will record all the results.
2. Working in groups of three lay the board flat on the floor. Using masking
tape, mark a starting line on the board. Mark a finish line on the floor 1.5
m beyond the bottom end of the board (Using masking tape mark the end of the
board on the floor). Place a barrier after the finish line.
3.Using textbooks prop up the other end of the board to make a slight
incline. Measure the height of the board from the floor. Record the height
in your data table.
a. Draw the ramp, indentify and label the height.
4.Have one person hold the tennis ball so that its even with the starting
line. As the holder releases the tennis ball, the other two students should
start their stopwatches.
5.One timer should stop his or her stopwatch when the tennis ball reaches the
end of the incline.
6.The second timer should stop his or her stopwatch when the tennis; ball
reaches the finish line.
•Practice 5 and 6 a few more times until comfortable with coordinating
starting and stopping the watches at appropriate intervals.
7.Repeat Steps 2, 4–6 two more times:
•Have one person hold the tennis ball so that its even with the starting
line. As the holder releases the tennis ball, the other two students should
start their stopwatches.
•One timer should stop his or her stopwatch when the tennis ball reaches the
end of the incline.
•The second timer should stop his or her stopwatch when the tennis; ball
reaches the finish line. Record the times to the bottom of the ramp and to
the finish line in the columns labeled Time 1 and Time 2.
8. Change the height of the ramp and repeat steps 4 through 7 three times
(multiple trials).
9. Change the height of the ramp again and repeat steps 4 through 7 three
times (multiple trials).
10. For each height of the ramps, complete the following calculations and
record them in your data table.
a. Find the average time the tennis ball takes to get to the bottom of the
ramp (Time 1).
b. Find the average time the tennis ball takes to get to the finish line
(Time 2).
c. Subtract the average Time 1 from the average Time 2.
d. Record the average speed.
Motion _ Skills Lab
Data Table
USE HARD COPY
Analyze and Conclude
Write your answers in the space provided.
1. Calculating How can you find the average speed of the tennis ball across
the floor for each height of incline? Determine the average speed for each
height and record it in your data table.
________________________________________________________________________
2. Classifying Which is your manipulated variable and which is your
responding variable in this experiment? Explain. (For a discussion of
manipulated and responding variables,see the “Conducting a Scientific
Investigation” handout or class notes)
________________________________________________________________________
________________________________________________________________________
3. Graphing Graph the speed of the tennis ball versus the height of the ramp.
_____________________________See attached Graph___________________________
4. Drawing Conclusions What does the shape of your graph show about the
relationship between the tennis ball’s speed and the height of the ramp?
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
6. Communicating:
a.Do you think your method of timing was accurate? Why?
b.Did the timers start and stop their stopwatches exactly at the appropriate
points? How do you know?
c.How could the accuracy of the timing be improved?
d.Write a procedure for your method.
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
