What is the difference between displacement and distance travelled

displacement is the distance moved in stated direction.

displacement is the starting point to the end point.

distance is the distance travelled in unit of time.

distance is the whole journey

here is an example:

so what is the displacement?

like I said before displacement is the starting to the end point.

so the displacement is 500km

and the distance?

distance is the whole journey

so it is 400+300=700km

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.

what type of charge does it have? negative