Asae grade 5, unf bolt carries a static tensile load of 2000 lb with a safety factor of 5 based on proof strength. the bolt is used with a nut made of steel of sae grade 1 specifications. (a) what size of bolt is required? (b) what is the least number of threads that must be engaged for the thread shear strength to be equal to the bolt tensile strength?

If a particle moves along a path such that r : (3 sin t) m and ? : 2t rad, where t is in seconds. what is the particle's acceleration in m/s in 4 seconds? a)- 16.43 b)- 16.29 c)- 15.21 d)- 13.79

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

Aquick transition of the operating speed of a shaft from its critical speed will whirl amplitude. (a) increase (b) limit (c) not affect (d) zero