What explains the result?
A ball and surface deform during impact; energy spreads into sound, heat, and deformation, changing rebound height.
PHYSICAL SCIENCE · GRADES 4–8
Bounce-energy comparison
INVESTIGATION QUESTIONHow does ball type change the percent of drop height returned on the first bounce?
● ILLUSTRATIVE SCIENCE MODEL
ENGLISH CAPTIONS
Mark one release height. Ball type is the planned factor; floor and starting height remain constant.
0.0 / 3.0 s
Where does this matter?
Rebound and energy loss matter in sports balls, footwear, and vehicle tires.
What should you keep in mind?
These percentages are illustrative model values. Ball pressure, release height, spin, floor material, and camera angle must remain consistent in a real test.
GRAVITATIONAL ENERGY · COLLISIONS · GRADES 6–10
Track the
bounce
Drop different ball types from the same height onto the same hard floor. Measure what percent of the starting height each ball returns on its first rebound.
FIXED 100 CM DROP TRACKTENNIS BALL · READY
120
110
100
90
80
70
60
50
40
30
20
10
0
SAME RELEASE · 100 CM
ENERGY PATHPE → KE → reboundsome energy → sound / heat / deformation
same 100 cm starting height measure the highest point of the first rebound
REBOUND DATA
Compare first-bounce height
Tennis ball
Not run
Basketball
Not run
Ping-pong ball
Not run
Rubber bouncy ball
Not run
*Teaching values: The bars only illustrate how a comparison may be logged; they are not experimental evidence. Record measurements from your own drops before drawing a conclusion.
ENERGY COMPARISON: At the highest point, gravitational potential energy is proportional to height (mgh). With the same drop height, rebound height ÷ drop height × 100 estimates the percentage of height returned. Mechanical energy transfers to sound, heat and deformation.
Applications: Sports balls, shoe soles and protective padding are tested for rebound and impact absorption. Rebound alone does not describe every performance or safety property.