Ididnt understand this question . could someone me ?

Explanation:

decelation =5m/s

u=25m/s

v=0m/s

t=?

then;a=(v-u)/t

t=(v-u)/a

but decelation is negative of acceleration

t=(0-25)/-5

t=5s

to find distance

s=ut+1/2at^2

s=25*5+1/2(-5)5^2

s=62.5m

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.

anchor = archer //