A balloon tied to the ground with rope floats in the air. The volume of the balloon is 1 L and the pressure in the balloon is 0.8 atm. If the balloon is placed deep underwater where it compresses so the pressure in the balloon is 4 atm, what will be the new volume of the balloon.

po-215 i got it right on the quiz

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.