Why does a ball bounce back up after it hits the floor?

When the ball hits the floor it squishes flat and stores the energy of its motion, like a squeezed spring. As it springs back to its round shape it pushes against the floor, and that push shoots it back up.

Why doesn't a ball of clay or a beanbag bounce?

Soft, floppy materials don't spring back to their original shape. Instead of storing the energy and releasing it, they absorb it, so the object just goes splat and stays where it lands.

Why does each bounce get lower than the one before?

Every time the ball squishes, a tiny bit of its energy leaks away as heat and sound. With less energy left for the next bounce, each bounce is a little lower until the ball finally stops.

What makes some balls bouncier than others?

Bounciness depends on how springy, or elastic, the material is. A more elastic ball stores and returns more of its energy when it squishes, so it rebounds higher; a less elastic one wastes more energy and bounces lower.

Does the floor matter for how high a ball bounces?

Yes. A hard surface like concrete returns most of the energy to the ball, so it bounces high. A soft surface like carpet or sand absorbs more of the energy, so the same ball bounces much lower.

Why Does a Ball Bounce?

Science Interactive lesson Free to play

A ball bounces because of how it changes shape when it hits the ground and how energy moves through it. When a moving ball strikes the floor, it squishes flat for a tiny fraction of a second. The energy of its motion does not vanish — it is stored inside the squashed ball, much like a compressed spring. Because the ball 'wants' to return to its round shape, it pushes back against the floor as it springs out, and that push launches it upward again.

Not every object bounces. Springy, elastic materials like rubber store and release this energy efficiently, so they rebound well. Soft, floppy things like clay or a beanbag absorb the energy and stay put. Each bounce of even a good ball is also lower than the one before, because a little energy escapes every time as heat and sound, so the ball eventually comes to rest.

The key ideas a learner picks up are elasticity (squish and spring-back), the storing and releasing of energy, and why energy loss makes bounces shrink — early, intuitive groundwork for physics concepts of energy and elastic materials.

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Boing!

🏀 Why Does a Ball Bounce? Drop a basketball and it springs right back up — boing, boing, boing! But drop a wet ball of clay and it just goes splat and stays there. Today you'll become a Bounce Detective 🔎 and discover the secret of the springy bounce. Tap Next when you're ready! Made for curious kids in Singapore 🇸🇬
The squish

🟠 Step 1: A ball squishes When a ball hits the floor, it does something very fast — too fast for our eyes to see! It squishes flat for a tiny moment, then pops back to its round shape. Press and hold the button to squish the ball, then let go to watch it pop back. 👇 Hold to squish 💡 A bouncy ball is made of springy stuff (like rubber). Springy things hate being squished — they push themselves back into shape!
Stored energy

⚡ Step 2: The squish stores energy When the ball squishes, the moving energy doesn't disappear. It gets stored inside the ball, just like a squeezed spring or a stretched rubber band. Slide to squash the spring → Stored springy energy Energy stored: 0 The more you squash a springy thing, the more energy it stores — ready to push back!
Push back up

🚀 Step 3: The energy pushes it up The ball wants to be round again. So it pushes against the floor as it pops back into shape. That push shoots the ball back up into the air. Boing! ▶️ Make it bounce! 🪨 A clay ball is not springy. It squishes flat but cannot push itself back, so all the energy turns into heat and shape change — no bounce!
Detective sort

🔎 Step 4: Bouncy or not? A good Bounce Detective can guess which things bounce. Springy = bounces. Soft & floppy = no bounce. Tap each thing to test your guess! Tested: 0 / 5
Lower every bounce

📉 Step 5: Why bounces get smaller Have you noticed each bounce is a little lower than the one before? Every squish leaks a tiny bit of energy as heat and sound (that's the "boing!"). So the ball can't reach as high. 🎬 Watch the bounces Quick think: Why does the ball finally stop bouncing? It runs out of stored energy It gets too heavy The floor pulls it down hard
You did it!

🎉 You cracked the case! The secret of the bounce: 1️⃣ The ball squishes when it hits the floor. 2️⃣ The squish stores springy energy inside it. 3️⃣ The ball pushes back into shape and shoots up. Boing! 4️⃣ Only springy things bounce — soft clay just goes splat. 5️⃣ Each bounce loses a little energy as heat & sound, so it gets lower until it stops. Great work, Bounce Detective! 🕵️ 🏀 Next time you bounce a ball, picture the tiny squish-and-push happening too fast to see!

Frequently asked questions

Why does a ball bounce back up after it hits the floor?: When the ball hits the floor it squishes flat and stores the energy of its motion, like a squeezed spring. As it springs back to its round shape it pushes against the floor, and that push shoots it back up.
Why doesn't a ball of clay or a beanbag bounce?: Soft, floppy materials don't spring back to their original shape. Instead of storing the energy and releasing it, they absorb it, so the object just goes splat and stays where it lands.
Why does each bounce get lower than the one before?: Every time the ball squishes, a tiny bit of its energy leaks away as heat and sound. With less energy left for the next bounce, each bounce is a little lower until the ball finally stops.
What makes some balls bouncier than others?: Bounciness depends on how springy, or elastic, the material is. A more elastic ball stores and returns more of its energy when it squishes, so it rebounds higher; a less elastic one wastes more energy and bounces lower.
Does the floor matter for how high a ball bounces?: Yes. A hard surface like concrete returns most of the energy to the ball, so it bounces high. A soft surface like carpet or sand absorbs more of the energy, so the same ball bounces much lower.

Why Does a Ball Bounce?

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Frequently asked questions

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