A helium balloon has a volume of 5.0 L at a pressure of 101.3 kPa. The balloon is released and reaches an altitude of 6.5 km at a pres- sure of 50.7 kPa. If the gas temperature remains the same, what is the new volume of the balloon? Assume that the pressures are the same inside and outside of the balloon.

they vary. it used to be meat, grain, bread, candy, beverages, donuts, and fruits/vegetables. now they added exercise in.

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.