You have available to you of two pump styles: pump A at 1000 gal/min produces a 100 dBA SPL at a given distance, and pump B at 500 gal/min produces a 90 dBA at the same position. For a noise control point of view, which combination of pumps would be most acceptable for developing a flow rate of 2000 gal/min? Explain.

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

Ariver flows from north to south at 8 km/h. a boat is to cross this river from west to east at a speed of 20 km/h (speed of the boat with respect to the earth/ground). at what angle (in degrees) must the boat be pointed upstream such that it will proceed directly across the river (hint: find the speed of the boat with respect to water/river)? a 288 b. 21.8 c. 326 d. 30.2

The drive force for diffusion is 7 fick's first law can be used to solve the non-steady state diffusion. a)-true b)-false