Measuring one second with a bouncing ball

[thorpie]

Hello
Theoretically any ball that bounces 1.225 metres high is in the air for one second. This is fairly precise, +/-4% time variance is +/- 10 cm height variance, so bouncing to a height of 1.13 metres is 0.96 seconds and to a height of 1.32 is 1.04 seconds.
The theory is at least dependent upon identifying when he ball “leaves” the ground, which part of the ball is “at 1.225” metres high, and what size ball becomes measurably affected by air resistance.
Is anyone aware of any recorded experiments that quantify how long a second is, with various bouncing balls. There seem to be lots of discussion on bouncing balls and degradation of height bounced but nothing on measuring one second of time, and I cannot think of a simpler way to measure one second of time accurately from base.
Thank you for your time
Glenn

 

[berkeman]

Hello
Theoretically any ball that bounces 1.225 metres high is in the air for one second. This is fairly precise, +/-4% time variance is +/- 10 cm height variance, so bouncing to a height of 1.13 metres is 0.96 seconds and to a height of 1.32 is 1.04 seconds.
The theory is at least dependent upon identifying when he ball “leaves” the ground, which part of the ball is “at 1.225” metres high, and what size ball becomes measurably affected by air resistance.
Is anyone aware of any recorded experiments that quantify how long a second is, with various bouncing balls. There seem to be lots of discussion on bouncing balls and degradation of height bounced but nothing on measuring one second of time, and I cannot think of a simpler way to measure one second of time accurately from base.
Thank you for your time
Glenn

I'd recommend using a large steel ball bearing bouncing off of a thick steel plate. That will give you very little loss in the bounces, and a more accurate measure of what you want to show, IMO.

I cannot think of a simpler way to measure one second of time accurately from base.

Base what?

 

[martane]

Hi Glenn,

That's a really interesting question! I haven't come across any specific experiments that measure the duration of one second using bouncing balls, but I did find a few studies that may be relevant.

One study from 2015 used a high-speed camera to capture the motion of a bouncing ball and compared it to theoretical predictions. They found that the ball's motion was affected by factors such as air resistance and the elasticity of the ball, which could impact the accuracy of using a bouncing ball to measure time.

Another study from 2019 looked at the effect of temperature and air pressure on the bounce height of a ball. They found that these factors can also affect the accuracy of using a bouncing ball to measure time.

Overall, it seems like using a bouncing ball to measure one second of time may not be the most precise method. However, it could still be a fun and educational experiment to try! Perhaps using a high-speed camera and controlling for factors like air resistance and temperature could help improve the accuracy of the results.

I hope this helps and let me know if you come across any other interesting studies on this topic!