2. El sistema de paredes se encuentra entre las temperaturas extremas de \( 100^{\circ} \mathrm{C} \) y \( 40^{\circ} \mathrm{C} \). Calcule el coeficiente de conductividad térmica de la pared central, sabiendo que las paredes primera y tercera tienen \( K=0.025 \frac{\mathrm{Cal}}{{ }^{\circ} \mathrm{Ccmseg} \text {. }} \) Todas las paredes son cuadradas de lado 10 cm . y espesor 2 cm .

Question 6/13An air tank is exposed to ambient temperature.If you set the air pressure of the tank to 35 psi for a leak test and find that 24 hours later the tank's pressure has increased, what could've happened?The tank leakedThe tank drew in additional airThe ambient temperature increasedThe ambient temperature decreased

4. When you descend in a plane, your ears pop. Is air moving into your ears or out of them when they pop? 5. Explain why a balloon gets bigger as you put more molecules of gas into it at a constant temperature.

body placed on a rough horizontal level \( W=75 \mathrm{~N} \) horizontal force affected 50 N Makes it about to move en the coefficient of friction equals \( \begin{array}{llll}\text { 1) } \frac{1}{3} & \text { 2) } \frac{2}{3} & \text { 3) } \frac{3}{4} & \text { 4) } \frac{1}{4}\end{array} \)

QUESTION 1: EPICYCLIC GEAR AND GEAR TRAINS An epicyclic gear train has a sun wheel with 24 teeth, and two planetary wheels of 46 teeth each, The latter mesh with the internal teeth of a fixed annulus with 116 teeth. The input shaft, carrying the sun wheel, transmits \( 4,5 \mathrm{~kW} \) at \( 280 \mathrm{r} / \mathrm{min} \). The output shaft is connected to an arm L that carries the planetary wheels. Calculate the speed of the output shaft.

body hanging by two strings and equilibrium \( T_{2}=60 \mathrm{~N} \) then \( w=\cdots \mathrm{N} \)