22k views

### How can you weigh your own head in an accurate way?

I read some methods but they're not accurate. They use the Archimedes principle and they assume uniform body density which of course is far from true. Others are silly like this one: Take a knife ...
240 views

### Detect original sound waves

I have just presented a project of mine regarding sound recognition using neural networks. I told during the presentation that I decided to only recognize one sound (musical notes coming from a guitar)...
12k views

### How Reynolds number was derived?

I'm studying fluid dynamics and recently the formula $Re=\frac{\rho vd}{\eta}$ was presented to me. I'm curious to know how Reynolds came up with this relations between this different variables. Did ...
1k views

### The sound energy when two or more objects collide

When two objects collide in an inelastic collision, some kinetic energy is converted to sound energy and heat. How do I determine how much of the kinetic energy is converted to sound energy? Provided ...
1k views

### Can dimension analysis be used in developing more advanced physics equations?

It is obvious that dimensional analysis can be used to derive many classical mechanics equations (excluding constants). As long as all the dependent quantities are known. My question is whether this ...
7k views

### Classic home experiments for an 8-year-old child [closed]

My 8-year-old daughter's school report says that she's good at understanding the basic science she's doing, but she's having trouble seeing how experimental results lead to conclusions. Specifically, ...
17k views

### The best way in which a man can pull a train

I have chosen this example as a paradoxical limit, but my question really regards the optimization, distribution and outcome of force when you try to pull a weight: how can you optimize your effort/...
426 views

### Can we measure temperature of a object just by the sound it makes?

I been thinking if temperature is a basic property of macroscopic objects rather than of quantum or microscopic objects and it is as a result of average kinetic energy of particles residing in the ...