# Bouncing ball investigation ```Experiment worksheet
3.5 Energy cannot be created or destroyed
Pages 50–51 and 172
Experiment 3.5: What if you bounced a ball?
Aim
To investigate the energy efficiency of a bouncing ball.
Materials
•
•
•
Tennis ball
Metre ruler
A selection of other types of balls
Method
1
Hold the tennis ball 1 metre above the ground next to the vertical ruler.
2
Drop the ball (do not throw it) on a hard surface.
3
Use the metre ruler to measure how high the ball bounces back. Be careful to avoid parallel error by
ensuring your eye is parallel with the ball.
4
Determine the percentage energy efficiency by using the formula below:
Percentage efficiency =
height of bounce 100

starting height
1
Inquiry: Choose one of the following questions to investigate.
•
What if another ball was bounced on the same surface? (Does it have the same efficiency?)
•
What if the same ball was bounced on another surface? (Does it have the same efficiency?)
Write a hypothesis for your inquiry.
What (independent) variable will you change from the first method?
What (dependent) variable will you measure/observe?
Write a list of variables you will need to control to ensure a fair test. Describe how you will control each
variable.
&copy; Oxford University Press 2017
Oxford Science 8 Western Australian Curriculum Teacher obook assess ISBN 9780190307172
Results
1
Complete the table below
INDEPENDENT
VARIABLE
HEIGHT OF BOUNCE
ATTEMPT 1
ATTEMPT 2
ATTEMPT 3
(SURFACE/BALL)
AVERAGE
HEIGHT OF
BOUNCE
FIGURE 9.27 Experimental setup
2
Using the space provided, draw a column graph showing how the energy efficiency of the
balls changed with your independent variable.
&copy; Oxford University Press 2017
Oxford Science 8 Western Australian Curriculum Teacher obook assess ISBN 9780190307172
EFFICIENCY
(PERCENT)
Discussion
1
Describe the results of your experiment.
2
3
•
What type of energy did the ball have:
before it was dropped?
•
just before it hit the ground?
•
as it touched the ground?
4
Where did the waste energy go?
5
Draw a flow diagram of the energy transformation.
&copy; Oxford University Press 2017
Oxford Science 8 Western Australian Curriculum Teacher obook assess ISBN 9780190307172