Consider a 6-legged water-treader with a mass of 200 mg (milligrams) and perfectly-non-wetting legs of total combined length 20 mm standing on a freshwater pond. The body density is p = 1200 kg/m³. The equation for the upwards surface-tension force that prevents the water-treader from sinking is given by F = 2y L cos 0, where 0 is the angle of contact between the water and the legs, y is the surface tension of the water, and L is the total length of the non-wetting legs. [Useful parameters: Freshwater density, p = 1000 kg/m³; surface tension of water, y = 0.07 N/m.] %3D (a) What is the contact angle, 0, between water and a perfectly-non-wetting surface? degrees %3D (b) Without considering surface tension forces, what is the apparent weight of this water-treader? Wapp %3D (c) What is the minimum length of non-wetting limbs that this water treader NEEDS in order to be able to balance its apparent weight with the surface tension forces? Give your answer in mm. L = mm %3D

Consider a 6-legged water-treader with a mass of 200 mg (milligrams) and perfectly-non-wetting legs of total combined length 20 mm standing on a freshwater pond. The body density is p = 1200 kg/m³. The equation for the upwards surface-tension force that prevents the water-treader from sinking is given by F = 2y L cos 0, where 0 is the angle of contact between the water and the legs, y is the surface tension of the water, and L is the total length of the non-wetting legs. [Useful parameters: Freshwater density, p = 1000 kg/m³; surface tension of water, y = 0.07 N/m.] %3D (a) What is the contact angle, 0, between water and a perfectly-non-wetting surface? degrees %3D (b) Without considering surface tension forces, what is the apparent weight of this water-treader? Wapp %3D (c) What is the minimum length of non-wetting limbs that this water treader NEEDS in order to be able to balance its apparent weight with the surface tension forces? Give your answer in mm. L = mm %3D

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

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