13. A helium balloon has a volume of 5.3L. If the volume increases to 10.6L and the pressure decreases to 9.24kPa, what is the initial pressure of the balloon?
18.5kPa
32.3kPa
0 4.75kPa
10.5kPa

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.

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.

the answer is 100. i just did this lesson and got a 100% on it. : )

-fishtank