The 150-mm-thick wall of a gas-fired furnace is constructed of fireclay brick (k = 1.5 w/m k, = 2600 kg/m3, cp = 1000 j/kg k) and is well insulated at its outer surface. the wall is at a uniform initial temperature of 20°c, when the burners are fired and the inner surface is exposed to products of combustion for which t[infinity] = 950°c and h = 100 w/m2 k. (a) how long does it take for the outer surface of the wall to reach a temperature of 750°c? (b) plot the temperature distribution in the wall at the foregoing time, as well as at several intermediate times.

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.

causes

fossil fuels burn

cities become more industrialized

human population grows worldwide