1. the self-diffusion coefficient of h2o molecules in water is 2.26 x 10-5 cm2 s-1 at 25 oc. estimate how long it takes for an h2o molecule in water to travel: a. 1.0 cm at 25 oc b. 2.0 cm at 25 oc c. 2.0 cm at 50 oc (this one will take some creativity…) hint: the argument in the error function relationship for fick's second law [x/(2*(dt)^.5] must be a constant since the error function is constant, therefore: x = k' 2 (dt)0.5 where x is the diffusion distance and t is time and d is the diffusion constant. we can just assume k' =1 which is not actually the case but at least can us get order of magnitude estimates for diffusion distances.

Clothing made of several thin layers of fabric with trapped air in between, often called ski clothing, is commonly used in cold climates because it is light, fashionable, and a very effective thermal insulator. so it is no surprise that such clothing has largely replaced thickand heavy old-fashioned coats. (a) consider a jacket made of five layers of 0.1-mm-thick synthetic fabric (k = 0.13 w/m·°c) with 1.5-mm-thick air space (k = 0.026 w/m·°c) between the layers. assuming the inner surface temperature of the jacket to be 28°c and the surface area to be 1.25 m2, determine the rate of heat loss through the jacket when the temperature of the outdoors is 0°c and the heat transfer coefficient at the outer surface is 25 w/m2·°c. (b) what would your response be if the jacket is made of a single layer of 0.5-mm-thick synthetic fabric? what should be the thickness of a wool fabric (k = 0.035 w/m·°c) if the person is to achieve the same level of thermal comfort wearing a thick wool coat instead of a five-layer ski jacket?

Apotter's wheel moves uniformly from rest to an angular speed of 0.20 rev/s in 32.0 s. (a) find its angular acceleration in radians per second per second. rad/s2 (b) would doubling the angular acceleration during the given period have doubled final angular speed?

In which type of system is power held solely by the central government and not shared with regional governments? group of answer choices federal unitary confederate oligarchic