(6 points) A cylinder has a radius of 12 mm and a length of 2.5 m. It is made of steel with a thermal conductivity of LaTeX: 53.4 \frac{\mathrm{W}}{\mathrm{m K}}53.4 W m K. One end of the cylinder is held at a temperature of LaTeX: 361^{\circ}\text{C}361 ∘ C, the other at LaTeX: 105^{\circ}\text{C}105 ∘ C. In steady state how much power will flow through the cylinder in the form of heat?

2.46 W

Explanation:

Thermal conductivity k = 53.4 W/m-K

Radius r = 12 mm = 12x10^-3 m

Lenght = 2.5 m

T1 = 361 °C

T2 = 105 ∘C

Area A = ¶r^2 = 3.142 x (12x10^-3)^2

= 0.00045 m^2

Power P = -AkdT/dx

Where dT = 361 - 105 = 256

dx = lenght of heat travel = 2.5 m

P = -0.00045 X 53.4 X (256/2.5)

= -0.024 X 102.4 = -2.46 W

The negative sign indicates that heat is lost from the metal.

d) physical means can be used to separate the components of air.

russian is not my first language, so i'm afraid i can't write out an answer in russian, but hopefully you can find a way to do so. here's my best translation of the problem: you're given a plot of a particle's position in one-dimensional space over time, and you're asked to find either the total distance traveled by the particle after 6 seconds had elapsed, or the total displacement of the particle after 6 seconds.

if you want the total distance traveled, you would first need to determine the particle's velocity as a function of time, then integrate that over the 6-second interval. we know the position function is quadratic with roots at 0 and 6, so we have

where is unknown. because the position is parabolic, there is symmetry about the midpoint at , and we know that

so that the position function is

which means the velocity is

then the total distance traveled is

so the total distance traveled is 20 m.

on the other hand, if you want to find displacement: the particle starts at and ends at , so its displacement is 0.