Your car travels 600 miles in 6 hours. You stop the car for lunch for 1 hour and then you continue on your trip for another 14 miles and finish the entire trip in 8 hours. What was your car's average speed while you were driving?

Average speed= 87.71 Miles/hour

Explanation:

The section of my journey while driving is divided ino two.

First section.

Distance covered = 600 miles

Time taken = 6 hours

Velocity or speed = distance/time

Speed = 600/6

Speed = 100 Miles/hour

Section two.

Distance traveled= 14 miles

Time taken = one hour ( because total time is 8 hours, first section is 6 hours, I spent one hour eating lunch, so it's remaining one hour for the 14 miles)

Speed = 14/1

Speed= 14 miles/hour

But average speed is total distance divided by total time taken .

Avg speed = 614 miles/7 hours

Avg speed= 87.71 Miles/hour

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.