CER AJUTOR IMEDIAT O placă dreptunghiulară cu lăţimea l = 1m şi lungimea L = 2m se încălzeşte cu 100ºC. Prin măsurare, un elev contată că lăţimea plăcii se măreşte cu 2mm (la încălzirea cu 100ºC).

Cu cât se dilată placa în lungime?

Calculati latimea si lungimea placii dilatate si aria acesteia.

Cu cât s-ar alungi o bară din acelaşi material având lungimea de 40m dacă s-ar încălzi cu 25ºC?

As part of an industrial process, air as an ideal gas at 10 bar, 400k expands at steady state through a valve to a pressure of 4 bar. the mass flow rate of air is 0.5 kg/s. the air then passes through a heat exchanger where it is cooled to a temperature of 295k with negligible change in pressure. the valve can be modeled as a throttling process, and kinetic and potential energy effects can be neglected. (a) for a control volume enclosing the valve and heat exchanger and enough of the local surroundings that the heat transfer occurs at the ambient temperature of 295 k, determine the rate of entropy production, in kw/k. (b) if the expansion valve were replaced by an adiabatic turbine operating isentropically, what would be the entropy production? compare the results of parts (a) and (b) and discuss.

You are traveling in a car going at a constant speed of 100km/h down a long, straight highway. you pass another car going in the same direction which is traveling at a constant speed of 80km/h. as measured from your car's reference frame this other car is traveling at −20km/h. what is the acceleration of your car as measured from the other car's reference frame? what is the acceleration of the other car as measured from your car's reference frame?

There are two routes similar in terrain; however, one route has an incline of approximately 28 degrees, and you must decide on which route to take. what is the maximum road grade that your fully loaded ecv can climb?