Problem $1$: A small aircraft $($Piper PA$-18)$ has an engine with a power of approximately $100KW.$

Its cruise speed is around $v=100k\frac{m}{h}.$ The engine is subjected to the structure through a plate

of $3$ mm of thickness and a set of six screws, as shown in Fig. $1.$ Knowing that the ultimate strength

of the plate is $150$ MPa $,$ and the material of the rivets is $250$ MPa $,$ compute:

A$-$ The diameter of the rivets.

B$-$ The distance between the center of the holes to the closest free surface of the plate.

Fig. $1$: Set up of the engine fixture to the airplane structure.

Hint: The trust of the engine is given by its power generation $P,$ as $T=\frac{P}{v}.$