A 12-ft chain weighs 24 lb and hangs from a 10-ft high ceiling. Find the work needed to lift the lower end of the chain to the ceiling so that it is level with the upper end

Step-by-step explanation:

We shall calculate work needed by knowing the distance by which centre of mass has been raised in the process .

center of mass is raised by

( 10 / 2 - 6 / 2 ) =  2 ft

h = 2 ft

g = 32 ft/s²

m = 24 lb

Work done = mgh

= 24 x 32 x 2

= 1536 units.

18

step-by-step explanation:

draw the shape and you will see that f and k are actually at adjacent vertices (points of the hexagon that are neighboring).   so find the distance between (1,2) and (4,2).   that is easy since (1,2) and (4,2) is just a vertical distance to count, which is 3.   it is a regular polygon which means all sides are congruent.   you have 6 sides (hexa) so multiply 6 by 3 to receive 18.

answer: 2530

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