By Coding in Matlab

A two-inch diameter craft ball is thrown vertically. This initial velocity of the ball is 20 ft/s

a) Neglecting drag, draw a free body diagram and formulate a first order ODE that governs the velocity of the ball. Is the ODE linear or non-linear?
for part a I got t= 0.62 second

b) To determine the drag coefficient effect, an experiment has been conducted that showed the terminal velocity of the ball (during a free fall) to be 20 ft/s. Use Euler’s method to estimate the "actual" time to achieve maximum elevation for the case that the ball is thrown up with the given initial velocity (20 ft/s).

Acommercial grade cubical freezer, 4 m on a side, has a composite wall consisting of an exterior sheet of 5.0-mm thick plain carbon steel (kst= 60.5 w/m k), an intermediate layer of 100-mm thick polyurethane insulation (kins 0.02 w/m k), and an inner sheet of 5.0- mm thick aluminium alloy (kal polyurethane insulation and both metallic sheets are each characterized by a thermal contact resistance of r 2.5 x 104 m2 k/w. (a) what is the steady-state cooling load that must be maintained by the refrigerator under conditions for which the outer and inner surface temperatures are 25°c and -5°c, respectively? (b) for power saving purpose, which wall material should be increased/reduced in. thickness in order to reduce 50% of the cooling load found in part (a)? redesign the thickness of the proposed material. 177 w/m-k). adhesive interfaces between the q=575.93 w