Hello Everyone, Welcome back to Motion Monday 👋 At first glance, a bouncing ball feels simple — But here’s the catch: In this study, three balls are dropped from the same height (500 mm) onto the same surface:
|
What is e (Coefficient of Restitution)?
It’s a measure of how “bouncy” a material is.
- e = 1 → Perfect bounce (no energy loss)
- e = 0 → No bounce at all
In simple terms, e tells us how much energy a ball gives back after hitting the ground.
Why does e matter?
When the ball hits the ground, energy is stored during compression and then released during rebound — but not all of it comes back.
Here’s the key relationship:
h₂ = e²h₁
- h₁ → Initial drop height
- h₂ → Rebound height
- e → Coefficient of restitution
- e² (e squared) → Energy ratio
(Represents how much energy is retained after impact)
Even small changes in e create large differences in bounce height.
The Motion :-
All three balls are dropped simultaneously.
The Path :-
True Height Comparison :-
What’s Really Happening?
- The Super Ball returns most of its stored energy → high rebound
- The Tennis Ball loses more energy internally → moderate bounce
- The Steel Ball, despite being stiff, dissipates energy quickly → minimal rebound
Same drop. Same conditions.
Completely different outcomes.
Takeaway
It’s not about how hard the ball hits the ground —
it’s about how efficiently the material gives energy back.
👉 Bounce height isn’t controlled by force… it’s controlled by energy recovery.
To Play with the motion yourself you can download SOLIDWORKS file from below.
| 3DPlay Model | Model Zip |
|
