Darya Ananyeva Voronezh-2 17. Starch monsters Darya Ananyeva Voronezh-2

2 Terms of the problem The water starch suspension was placed on the membrane on a loudspeaker. Investigate and describe the resulting starch monsters

The objectives of the work are as follows: 3 The objectives of the work are as follows: • to identify the composition of the starch mucilage suitable for emergence of “monsters”; • to examine dependence of formation of monsters upon the sound frequency.

4 Non-Newtonian fluids

5 Such a “solution” can be poured (or rather put) on the speaker of a music center. Playing different sounds and changing the volume, we achieved the result that the starch began to rise and acquire amazing shapes

6 When we mix starch with water, it does not dissolve completely, and floats in the form of tiny lumps in the water. Each lump is a coil of starch strands. The coils are also interconnected with the starch strands acting like tiny springs

7 The sound acts like a blow – the solution is compressed in certain areas, it becomes hard, and those parts of the solution begin to be ejected from the liquid, just like an empty plastic bottle is pushed out of the water

8 Experimental part Equipment starch mucilage camera loudspeaker

9 begin to appear at a frequency of 20 Hz

10 40 Hz

11 50 Hz

12 Monsters quit to appear at a frequency of 70 Hz

13 Water taken along with starch in the ratio of 50:50, Water is the best ingredient for preparation of starch mucilage. “Monsters” begin to appear at a frequency of 20 Hz and quit to appear at a frequency of 70 Hz.

14 Thank you for your attention!

Sources of information 15 Sources of information https://en.wikipedia.org/wiki/Non-Newtonian_fluid