2B-ii) Turn that into a dimensionless scale (convert one value into the other units so that units cancel, making it dimensionless), and invert it so that you have the value for 1 mm on photo = U mm on Mars (or 1 m on photo = U m on Mars), and write it in (a) as "1/U", where U is a large number (that's your dimensionless fractional scale, like "1/58,235") and for (b) rewrite that by dividing it through to get the dimensionless decimal scale, like "0.000017171745". Scale = map/eal. Show work after end of 2B-iii: a) dimensionless fractional scale b) dimensionless decimal scale "1 unit map / X units real" now divide through 2B-ili) a) crater length in Z m on Mars = crater length in W mm on photo * X m / mm scale factor (Solve for Z) b) m crater length in Z m on Mars = crater length in W mm on photo * m D'less decimal scale mm c) U from d'less fractional scale m crater length in Z m on Mars = crater length in W mm on photo * mm Z in m crater real W in m Rover real Note that (c) was just a rearrangement of ------- -- = --- W in m crater on photo V in m Rover on photo 3A) (4 pts) Below is a simple map with two X's and a scale bar that represents 10 km. Report ruler lengths to 0.01 cm How far is it (in the real world) between the centers of the two X's, to .01 km? Scale, length on ruler* X-X distance on ruler* Distance on ground to 0.01 km X 10 km X Set up a proportionality between the XX distance in km on the ground, the scale bar distance in km on the ground, the XX distance in mm on your ruler, and the scale bar distance in mm on your ruler, and solve for the real XX distance.. 3B) Calculate 10 km scale bar / x mm scale bar, = 10 /_ km / mm That's your km / mm scale factor, which is half of your proportionality already set up. After that, X km between two points = Y mm on map between the two points * Z km on ground / mm on map scale factor 3C) Confirm that using the scale factor gives you the same answer as 2A: 8