How could you make a timer that goes for 15 seconds out of the materials that you have at home?

Question

how do you think i could make something thst lasts for 15 seconds out of the materials in an average household?

Answer 1

Take an empty, dry 20 ounce pop bottle. Fit a washer over the opening--tape it on, making sure not to cover the hole. Place a funnel over the hole in the washer. Pour salt through the funnel at full speed for 15 seconds. When the time's up, immediately remove the funnel from the washer. Take another empty 20 ounce bottle and place it mouth to mouth with the other pop bottle, with the washer still in place. Duct tape them together at the necks of the bottles. You've made an hourglass-ish 15 second timer.

edit--Remove the labels, so it's easy to see the salt flowing and when it stops.

Answer 2

It's cheaper just to go 99 cents store and just get a cooking timer for $1.00 dollar.  Why bother with all that stuff u have at home?  and such a mess !

Answer 3

It depends on what you have in your home and what do you want the timer to do when the 15 seconds is over. If you want it to close a switch maybe you could have a switch connected to float which would be in a tank of water with a drain hole of the proper size. Maybe you could have an Alka Seltzer tablet (or something similar) used as a wedge to block action of some mechanical device which when immersed it would disinigrate, allowing the device to activate.