The wall of a furnace is made up of inside layer of silica brick 120 mm thick covered with a layer of magnetite brick 240 mm thick. the temperature at the inside of the silica brick wall and the outside surface of magnetite brick wall are 7250c and 1100c respectively. the contact thermal resistance between the two walls at the interface is 0.00350c/w per unit wall area. if the thermal conductivities of the silica and magnetite bricks are 1.7 w/m0c and 5.8 w/m0c, calculate: a. the rate of heat loss per unit area of walls, and b. the temperature drop at the surface.

After the near spacecraft passed mathilde, on several occasions rocket propellant was expelled to adjust the spacecraft's momentum in order to follow a path that would approach the asteroid eros, the final destination for the mission. after getting close to eros, further small adjustments made the momentum just right to give a circular orbit of radius 45 km (45 × 10^3 m) around the asteroid. so much propellant had been used that the final mass of the spacecraft while in circular orbit around eros was only 545 kg. the spacecraft took 1.04 days to make one complete circular orbit around eros. calculate what the mass of eros must be.

Which simple machine is not part of this compound machine? a. lever b. pulley c. inclined plane d. wheel and axle

Write the correct abbreviation for each metric unit