A 100-kg object is moving at 20 m/s when a force brings the object to rest 3 points
in 1.5 seconds. If the same object moving at the same initial speed was
brought to rest in 3.0 seconds, then the required force would be
times the original value. Fill in the blank with the factor that would make
the statement correct. Then explain, in detail, how you picked your answer.

0.5

Explanation:

By reducing the force, the time taken to stop the object increases, as they are inversely proportional.

Therefore, when a doubling of the time is observed, a halving of the force should be as well.

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.

power out to power in less than 100%