Force = mass x acceleration. what is the correct unit of force?

a. kgm/second/second or newton

b. meters/second

c. kg/second

d. meters/second/second

The only thing in that messy list of choices that can be a unit of force is the Newton.

But this is not to say that choice-A is entirely correct ... "kgm/second/second" is pretty meaningless, and is NOT the same thing as a Newton.

1 Newton = 1 kgm-meter/second/second

choice-B . . . . . unit of speed

choice-C . . . . . rate of change of mass; no name

choice-D . . . . . unit of acceleration

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.

e) none of the above answers are correct