Please help me with my homework..ive been trying for ages!?

Question

Well ive got some homework and i dont know if its right or not, i cant check because my teacher took in our books (with ALL of our working on it) so please help

and dont be offensive. maths is difficult. i would appreciate some help.

1.On a map of scale 1:100 000 the distance between Tower Bridge and Hammersmith bridge is 12.3cm . What is the actual distance in KM?

am i right? 12.3 x 100 000 = 1230000
actually is it divide? PLEASE HELP!

and

2. The distance from herford to st albans is 32km. how far apart will they be on a map scale 1:50 000

HELP!

thank you

Teresa.

Answer 1

You are correct. Multiple the measurement on a map by the scale to get the actual distance on the ground. Divide the distance on the ground by the scale to get the measurement on the map.

You may want to also convert cm to km when you get the answer. (Divide by 100,000) Normally you give distance between cities in km not cm. Do the opposite to get from km to cm.

Answer 2

You are very close.
1. If the distance on the map is 12.3 cm, then it would make sense that in REAL life, the distance is 12.3 * 100 000 cm, or 1,230,000 cm.

However it asked for distance in KM. 100,000 cm in 1 km. So now you have do DIVIDE your number by 100,000.
So your answer is 12.3 KM.

2. Now you have an actual distance of 32km. On a map scale 1:50000, you will have to divide. 32/50000 = 0.00064 KM.
Now you can convert that into CM to make things easier: 0.00064 * 100000 = 64 CM.

You are on the right track, if you think through the questions logically rather than just trying to guess if you should multiply or divide you will be successful in the future! Good luck!

Answer 3

"am i right? 12.3 x 100 000 = 1230000
actually is it divide? PLEASE HELP!"

Well, think about it. Is the map bigger or smaller than real life? If the map is bigger than real life, then you need to divide, because the map is a representation that is bigger than what it is showing.

However, I think in your case the map is smaller than real life. This can be verified by the 1:100000 ratio. This means one unit on the map represents 100000 of that unit in real life. In this case you multiply.

The key to your question is units, which you haven't given. If the map scale is 1cm:100000cm then you have the answer correct, except for units. 1km = 100000 cm, so in the case of your question 12.3cm = 12.3km.

2.) Think about what I said to start with. Is the map bigger or smaller than real life? Smaller obviously. So to go from real life to the map you must divide. Your answer would be

32km/50000 = ?

Also, note the scale units for this one as well.

Answer 4

the scale means 1of any unit on the map = 100,000 of the same unit in the real world. or 1 = 50000 in the second ?.
you got the first one right but you have to convert your answer from cm to KM by divding by 10000 ( the # of cm in a KM.)
For the second one, if 1 cm on the map = 50,000 cm in the real world that would mean that one cm on the map would also equal 5km on the map (50,000/10,000). so divide 32 by 5 and that will give you your answer in cm.

Answer 5

Teresa,

You are on the right track.

1. Good answer except you need to convert to km from the cm you have. Try to divide by 100,000....You have 12.3 km

2. Do the same in reverse (32 / 50,000 = 0.00064 then multiply by 100,000 should give you the answer).

You are well on your way. Good Luck!

Answer 6

first take the ratio of map scle to actual scale
let map scale = d(map)
actual scale =d(act)
d(map)/d(act) = 1/100000
then equate the ratios
d(map)/d(act) = 1/10^5 = 12.3/d(act)
cross multiply
12.3*10^5 cm = 12.3*10^5/10^5 km = 12.3 km
2)
d(map)/d(act) = 1/50000 = d(map)/32
cross multiply
d(map)50000 = 32
d(map) = 32/50000 km = [(32/5*10^4)]*10^5 cm
320/5 cm = 64 cm

Answer 7

1. Right, except that you have to convert now from cm to km. To do that, divide by 100,000.

So, you get 12.3 km.

2. Do the same.

Answer 8

1. 12.3cm x 100 000 = 1230 000 cm = 1.230 km

2. 32 km/50 000 = 64 /100 .000 km = 64/100 m = 64 cm

Answer 9

I assume your scale is cm:cm.

Question 1:
1cm:100,000 cm
c means "centi", or 1/100, or 0.01, or 10^-2
k means "kilo", or 1000, or 10^3

100,000 cm = 100,000 x 10^-2 m, or 1000 m, or 1km
Therefore, the scale is 1cm:1km, so

12.3cm = 12.3km

Question 2:
1cm:50,000cm
50,000 cm = 500 m, or 1/2km
1cm = 1/2km, then
2cm = 1km, or
1km = 2cm

Therefore,
32km = 32 x 2cm
32km = 64cm

Answer 10

1. Correct. You should convert it to more meaningful units though. To convert centimeters to kilometers multiply by 100,000.

12.3km

2. Opposite of the first question. Divide by 50,000 to get the distance on the map in km (0.00064) and multiply by 100,000 to get the distance in centimeters.

64cm