A furnace wall consists of 25 cm firebrick, 30 cm insulating brick and 25 cm building brick , respectively. The inside wall is a temperature of 800C and the atmospheric temperature is 15 degrees * C C. Calculate the heat loss per of wall area and the temperatures of the interfaces of the furnace. The heat transfer coefficient for the outside surface is 10 W/m^ ^ 2.k and the thermal conductivities of the firebrick , insulating brick, and building brick are 6, 0.3 and 0.8W / m respectively. m^ ^ 2; tc=^ * 1 point t 1 =800^ C; t a iota c; t 2 =15^ o; 86.363 degrees * C 73.148°C 74.059 degrees * C; 68.983 degrees * C

One form of energy can be another type of energy. a. created to form b. transformed into c. destroyed and then created to form

Amass m = 74 kg slides on a frictionless track that has a drop, followed by a loop-the-loop with radius r = 18.4 m and finally a flat straight section at the same height as the center of the loop (18.4 m off the ground). since the mass would not make it around the loop if released from the height of the top of the loop (do you know why? ) it must be released above the top of the loop-the-loop height. (assume the mass never leaves the smooth track at any point on its path.) 1. what is the minimum speed the block must have at the top of the loop to make it around the loop-the-loop without leaving the track? 2. what height above the ground must the mass begin to make it around the loop-the-loop? 3. if the mass has just enough speed to make it around the loop without leaving the track, what will its speed be at the bottom of the loop? 4. if the mass has just enough speed to make it around the loop without leaving the track, what is its speed at the final flat level (18.4 m off the ground)? 5. now a spring with spring constant k = 15600 n/m is used on the final flat surface to stop the mass. how far does the spring compress?

The temperature in gavin's oven is a sinusoidal function of time. gavin sets his oven so that it has a maximum temperature of 280°f and a minimum temperature of 240°. once the temperature hits 280°, it takes 20 minutes before it is 280° again. gavin's cake needs to be in the oven for 30 minutes at temperatures at or above 270°. he puts the cake into the oven when it is at 260° and rising. how long will gavin need to leave the cake in the oven? (round your answer to the nearest minute.)