That is an excellent question, and luckily it is even the type of question that you can answer yourself through experimentation. Below I will outline a scientific experiment that you can do to find the answer to your question, but in case you don't have the time, I'll also tell you what is happening.

When we inflated a basketball we are filling it with lots of air. Basketballs are actually very similar to balloons, except that they have thicker, harder skins. The more air we pump into them the more squished the air has to become to fit inside the ball. As the air becomes more squished, it pushes more on the inside of the ball. When you have a ball which is more inflated, there is more force pushing on the inside of that ball. (We call that air pressure). When a bouncing ball hits the ground, you are temporarily pressing on the ball which squishes the air even more. The air doesn't like this, and presses back with a certain force. That force is what causes the ball to come back up. With more air in the ball, the air starts at higher pressure and pushes back that much harder when the ball is bounced.

So that short answer is that more inflated basketballs bounce better because they have more air pressure inside them.

This is easy to test. Just get an inflatable ball and a pump. Have an adult help you take most of the air out of the ball, then try to bounce it. Look at how high it bounces. Then use the pump to put a bit of air into the ball. Again, look at how high it bounces. Do this several times, until the ball is completely inflated. This simple experiment involves all aspects of true science. You begin with a question, design an experiment, make observations and then draw a conclusion.

I hope that helps. Thanks for the question.

Inflated basketballs bounce better than flat basketballs. Have you tried playing basketball with a flat ball? It's hard!

What is the difference between an inflated basketball and a flat basketball? An inflated basketball contains more air. Now, a basketball can be thought of as a spring. When you compress or squeeze a spring, what does it want to do? It wants to spring back to its original shape. Basketballs are just like springs; the air in a basketball is like the metal coil of a spring. A basketball filled with air prefers to be shaped like a sphere, but when you throw it at the ground, it gets squished on impact. The air inside is then at a higher pressure and wants to return to a lower pressure. A basketball bounces because the pressure of the air inside of the basketballs restores it to its original shape after it is squished. The more air you have in a basketball, the better it springs!

Yes, fully inflated basketballs do bounce better than flatter ones. When a ball has more air inside of it, there is more pressure which causes the material of the ball to be less floppy and deform less when bounced. Also, when there is more air there is a greater force acting against the ground upon impact.

Yes, basketballs that are inflated more do bounce higher than flatter ones. The extra air makes it so the ball is harder. Think about throwing a pillow at the ground. When it hits the ground, it doesn't bounce back, it just flops and sits still. If you have a basketball that has gone really flat, it will do the same thing. It may bounce back just a little bit, but not very much.