BrainDen.com - Brain Teasers

# Ball

## Recommended Posts

The Ball - Back to the Logic Puzzles

How can you throw a ball as hard as you can and have it come back to you, even if it doesn't bounce off anything? There is nothing attached to it, and no one else catches or throws it back to you.

This old topic is locked since it was answered many times. You can check solution in the Spoiler below.

Pls visit New Puzzles section to see always fresh brain teasers.

Ball - solution

Throw the ball straight up in the air.

How can you throw a ball as hard as you can and have it come back to you, even if it doesn't hit anything, there is nothing attached to it, and no one else catches or throws it?

##### Share on other sites

• 4 weeks later...
• Replies 328
• Created

#### Popular Days

This is not as elegant a solution, but...

If you were on a planet with just the right mass and diameter, you're hardest throw in the right direction would allow the ball to orbit the planet once (or twice, etc. depending on the constants just mentioned).

##### Share on other sites

Could you not throw the ball up a slope/hill? Does that count as the ball hitting something (the ground)?

##### Share on other sites

Could you not throw the ball up a slope/hill? Does that count as the ball hitting something (the ground)?

That would not fit the initial condition of not hitting anything.

##### Share on other sites

I am assuming that we are throwing this ball on the planet Earth...so in the answer the ball can be touching air and using the force known as gravity.

One solution is to throw the ball directly into a stream of circular air (possibly a tornado/hurricane....but those are a bit dangerous) and catch it on the way back.

##### Share on other sites

My solution was that, while throwing the ball, you rotate it towards you, so once it hits the ground it will get back.. does that count as valid?

##### Share on other sites

What if I threw it up at an angle, and then ran as quickly as I could and simply caught it as it came back down at the far end of the arc? Nobody said that I had to stand in one place.

##### Share on other sites

• 2 weeks later...

Well, technically speaking, to throw the ball straight up and to let it orbit the planet once first are one and the same. In both cases, you accelerate the ball away from gravity without achieving escape velocity, then gravity pulls it back around in an orbit. Standing on Earth and throwing it straight up, you have a very eccentric orbit that crosses paths with the planet's surface--meaning it'll come out of orbit very rapidly before it actually makes a complete revolution--but you are essentially doing the same thing either way.

Also, technically speaking the ball hits billions of air molecules on the way up, but the scenario would work the same without air. If you want to allow contact with air, you could spin it really, really fast, and make it come back to you like a boomerang, or do like Clarinetman suggested and throw it into a stream of moving air. I've actually shot arrows at an angle away from me so they came back to me with the wind, but I was still relying a lot on gravity.

Or you could have a transforming ball that converts to a flying machine after you throw it, like those little bombs the Green Goblin uses in Spiderman!

##### Share on other sites

Well, I was going to say throw it really hard and fast in a straight line, so hard that it goes right round the planet. It'd be a bit hard, though.

Another possible one takes the assumption that the ball was made of metal (like a shot-putt) and you had an industrial strength magnet (the type you need a license for), but if that was the case it'd be impossible to do, as the magnet would go with the ball.....

##### Share on other sites

What about a junkyard-strength electromagnet? They can lift entire cars with them, so surely it could pull the ball back, then you just flip the switch to off and you've got the ball back. To avoid contacting anything, you could just time the electromagnet so it turns off before the ball hits it, and you catch it in mid-air. Of course, you'd want to make sure you aren't wearing anything metallic when you turn the electromagnet on.

##### Share on other sites

holy cow. there are a lot of smart people out there with a lot of time on their hands or they are just that smart to know these things off the top of their heads. jeeze.

##### Share on other sites

For all of you skateboarders out there:

Throw the ball around a 3/4 pipe. If you did this correctly, the ball would never 'hit' anything per se, it would simply roll all the way around (IF you threw it hard enough and the 3/4 pipe were small enough).

##### Share on other sites

• 3 weeks later...

Of course if y'all can throw the ball as hard as i can, you can make it orbit the earth even 6 feet from the ground!!! WHAT! KING KONG AIN'T GOT NUTHIN' ON ME!

##### Share on other sites

come on people

throw the ball very hard toward you other hand and catch it, throw it from the right hand toward the left hand and catch it.

##### Share on other sites

>Or you could have a transforming ball that converts to a flying machine after you throw it, like those little bombs the Green Goblin uses in Spiderman!

Of course!

##### Share on other sites

holy cow. there are a lot of smart people out there with a lot of time on their hands or they are just that smart to know these things off the top of their heads. jeeze.

you don't know the half of it

##### Share on other sites

If it is an 'airball' you are playing with.

If it is a coors 'partyball' and you drank it yourself...it'll come back for you in the morning!

If you throw a charity ball, Etc.

what do u think for outside the box solutions? I believe airball is a very strong solution.

##### Share on other sites

All you do is throw it in the air right? wouldnt that make sence? You COULD concider the ground *hitting* something, due to the fact that it could slow it down.

i dunno... just my opnion.

##### Share on other sites

Or you could throw it on a small moon, or it could be a headbangers ball, I hear those guys rock pretty hard.

##### Share on other sites

All you do is throw it in the air right? wouldnt that make sence? You COULD concider the ground *hitting* something, due to the fact that it could slow it down.

i dunno... just my opnion.

You're absolutely right =)

##### Share on other sites

Throwing the ball straight up in the air, will make it hit something. It hits the point of flight where its enertia is no longer big enough to defy earths gravitational pull.

##### Share on other sites

• 2 weeks later...

Throw the ball directly up "What goes up, must come down."

##### Share on other sites

<!-- s:idea: --><!-- s:idea: --> why not just attach a bungee cord to the ball so it wouldn't actually be "hitting" anything but being pulled by something when u throw it. <!-- s:mrgreen: --><!-- s:mrgreen: -->

so when u throw it it automatically comes back to u.

##### Share on other sites

Just throw the ball as hard as you can up. What goes up must come down

##### Share on other sites

one time I shot an arrow as far as I could, so far I couldn't see it anymore. I waited and waited and waited. then all of a sudden here it came, rushing toward me. I was so excited, it came back. now, my depth perception, not so good.

##### Share on other sites

This topic is now closed to further replies.