1. Determine which of the following binary operations on Nare associative, have a (left or right) identity element, and contain

two different elements that commute:
(a) m* n = m + 2n.
(b) m* n= m’n.
(c) m* n= m.
(d) m* n = mn.​

What precautions should you take to prevent injuries when dealing with heavy loads?

What difference(s) did you notice using a pneumatic circuit over hydraulic circuit. explain why the pneumatic piston stumbles when it hits an obstacle.

Ajournal bearing has a journal diameter of 3.250 in with a unilateral tolerance of 20.003 in. the bushing bore has a diameter of 3.256 in and a unilateral tolerance of 0.004 in. the bushing is 2.8 in long and supports a 700-lbf load. the journal speed is 900 rev/min. find the minimum oil film thickness and the maximum film pressure for both sae 20 and sae 20w-30 lubricants, for the tightest assembly if the operating film temperature is 160°f. a computer code is appropriate for solving this problem.