Aerial View Maps

trouble with these three Geography R.F scale and Bar scale questions?

I am stuck on these few questions ive looked all over for help and no one or no site seems to really help if anyone has an idea how i can solve these problems so i know the basic formula id really appreciate it . Question 1. A map of unknown scale shows two tv transmitting towers. On the map the towers are 1/2 inches apart and the actual ground distance between them is 1,000 feet. What is the R.F. of the map? Question 2. A straight stretch of road on an aerial photograph was found to be 500 yards long. The same road segment measured on a the photograph was three fourths of an inch. What is the R.F. of the photograph? Question 3 This one is real confusing because it doesnt give you much to go on or what to do. it shows a rectangle with to lines on the first line it is 1 0 1 2 3 4 5 6 7 8 9 10 and says kilometers underneath the second line goes.. 1 0 1 2 3 4 5 and says miles underneath the question goes like this...The bar scales shown appear on one of the new U.S.G.S. maps.(A) Derive the R.F. of the map first using the kilometer scale. (B) no do it using the mile scale (C) which of the two systems was easier to using in the derivation of the R.F.and why.. I dont know what or how to measure that...if anyone can help explain these three problems id really appreciate it. thank you very much for your help it is really appreciated ..i just had one problem ..with question one i get that you have to convert ...and there is 12 inches in a foot ...and you multiply that by a 1000 to get 12,000...but since the questions says its 1.2 inches...why do you then mulitply it by two?...if one inch is equal to 12,000 how can the remainder .2 be worth the same? sorry it is just confusing to me...thank you very much if you can help break that one down a little more

Public Comments

1. Question 1 Convert everything to the same units. It would be 1/2 inch to 12,000 inches. Multiply with 2 to get scale as 1 : 24000 Question 2 3/4 inch to 500 yards (= 36 X 500 = 18000) since there are 36 inches to a yard. 3/4 : 18000; on multiplying with (4/3) 1 : 24000 Question 3 Take a scale, apply it to the rectangular bar and measure. Align the '0' of the scale to the '0' marking on the bar (strip). Read out the kms reading corresponding (aligned to) to 1 cm (=10 mm). If it is 24 km (say). Then the ratio is 10mm : 24 km (=24,000 mtrs = 24,000,000 mm). So it is 1 : 2,400,000 [1 to 2.4 million scale] For the miles scale align 1 inch (1") on the scale to the equivalent number of miles. Some times you need to measure more inches to exactly coincide with a miles reading, say 3.8 inches corresponds to 6 miles; convert miles into inches (X 5280 X 12) 3.8 : 6 X 5280 X 12 3.8 : 380160. It is 1 : 100,000 allowing for the (permissible) inaccuracy of measurement.