(b) an example of an inverse square field is the gravitational field f = −(mmg)r/|r|3. use part (a) to find the work done by the gravitational field when the earth moves from aphelion (at a maximum distance of 1.52 108 km from the sun) to perihelion (at a minimum distance of 1.47 108 km). use the values m = 5.97 1024 kg, m = 1.99 1030 kg, and g = 6.67 ✕ 10−11 n·m2/kg2. (round your answer to two decimal places.)

because it says use -2,0,and 2 for x, we can plug those numbers into the equation. y/4=3/4(-2)+2   y/4= -1 1/2 +2 now to get x by itself, we can multiply each side by 4. y=-6+8 which equals y=2 when x=-2. now you can do the same thing with 0 and 2 as x. you get y=8 when x=0 and y=14 when x=2.

x   |   y

-2 |   2

0   |   8

2   |   14

+15-35=-20

going in opposite directions

the answer is the index of refraction of the second medium is higher. i just took the test.