Speed of sound with a ball on the end of a string

[whoeli]

When I was younger I had a ball on a string. For what it's worth, the ball was quite a dense rubber, and about two inches in diameter and spherical, so I think it weighed about two-and-a-bit ounces, maybe two-and-a-half. The string was about a metre long, and it was very stretchy...

Once I took it outside and swung it over my head like a bullroarer (like this guy: ). The string stretched out, but stayed intact, so as the ball swung around me it gave a "circle" of about 11 metres' diameter... and since I remember I managed to get about six revolutions per second, the ball was traveling about 210 metres per second.

Aside from a bang (?), what would have happened had I managed to get the ball to move faster than sound? (That's what I was trying to do but I just... couldn't... do it.)

 

[eljose79]

Hello there,

Thank you for sharing your experience with the ball on a string. I can provide some insights into what would have happened had you managed to get the ball to move faster than sound.

First, let's talk about the speed of sound. The speed of sound in air at sea level is approximately 343 meters per second. This means that sound travels at 343 meters per second through the air. When an object, like your ball, moves faster than the speed of sound, it creates a shock wave known as a sonic boom. This is the loud bang you may have heard in your experiment.

If you had managed to get the ball to move faster than the speed of sound, it would have created a sonic boom as it traveled through the air. This would have been a very loud and intense sound, similar to the sound of a jet breaking the sound barrier.

In addition to the sonic boom, the ball would have also experienced a lot of resistance and drag from the air as it moved at such high speeds. This could have caused the ball to lose control and potentially break free from the string.

Furthermore, the ball's density and size would also play a role in its ability to break the sound barrier. A denser and larger object would require more force to reach supersonic speeds, making it harder for your ball to achieve this.

In conclusion, had you managed to get the ball to move faster than sound, it would have created a loud sonic boom and may have also caused the ball to lose control due to air resistance and drag. However, as you mentioned, it is unlikely that the ball would have been able to reach such high speeds due to its size and density.

I hope this information helps to satisfy your curiosity about what would have happened if you had achieved supersonic speeds with your ball on a string experiment. Keep exploring and experimenting, and you never know what new discoveries you may make.