Recall that one application of a Stack is to process an arithmetic expression written in postfix notation. We can also represent arithmetic expressions as a tree. Your job is to write a function that will convert a Stack
of singleton expression nodes (where all the left and right pointers are initially set to NULL) into the correct
tree structure. Note that you do not need to actually calculate the “answer” to the arithmetic expression.
Here is an example:

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false

Hydraulic fluid with a sg. of 0.78 is flowing through a 1.5 in. i. d. pipe at 58 gal/min. the fluid has an absolute viscosity of 11.8 x 105 lbf-sec/ft2. is the flow laminar, turbulent or within the critical range? give both a numerical reynolds number and a term answer.