# Talk:Scale models

Good stuff. Heath 01:02, 9 June 2008 (UTC)

can someone please explain to me why time is scaled down (sped up) by a factor that is equal to the square root of the factor by which length is scaled down.

I think that may be an error. In part of the description it mentions "every 2 seconds in the model it would be every 10 seconds in the full sized version" but later reverses the order of model Vs. real. I'm pretty sure the correct version is that the model moves faster than real life because a larger object would have to take more time to move a greater distance, so slow down the small model to replicate the larger version. DM8954

The speed of a wave is proportional to the square root of the length. If you hear about "hull speed" in a boat, it is the speed of a wave as long as the boat. In order for a model to have the wave as long as the boat move at the right speed relative to the model, we have to scale time this way.

I think what you said is correct, but where did you see "later reverses the order"? Vincecate 03:01, 1 June 2009 (UTC)

"If you want to do 1:25 scale model of 8 foot waves with a period of 10 seconds then waves in the model should be 4 inches high with a period of 2 seconds." ... oh, oops. I misread that. I guess there is no error. I can't tell if it's the wording or the fact that I was looking for/expecting an error based on the original comment. Sorry for the confusion. --DM8954 00:29, 3 June 2009 (UTC)

- I reworded that part trying to make it clearer. Is it less confusing now? Vincecate 15:13, 5 June 2009 (UTC)

That does help... but it was probably just my mistake in the first place. Thanks for posting this information, by the way. It'll be very useful. --DM8954 00:01, 7 June 2009 (UTC)