A weightlifter raises a 200 kg barbell with an accelaration of 3m/s2. how much force does the weightlifter use to raise the barbell?

u=13

v=30

s/t=u+1\2at

=13+431/2

=13+265.5

=278.5

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.

the amount of current in the coil