Determine the required number of active coils and permissable deflection in a helical spring made of 1.6 mm diameter steel wire, assuming a spring index of 6 and allowable stress of 345 mpa in shear. the spring rate is to be 1.75 n/mm.

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