What is the best way to determine the phenotype of a birds feathers ?

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.

wire in brush may conduct electricity from cell to drill and vice versa electrc shock possible

the answer to this is proletariats.

hope this : )