# Thread: Formula for calculating the distance....

1. ## Formula for calculating the distance....

The Formula for calculating the distance (d) in kilometres to the horizon is:

d= 8 [that tick like symbol] h/5 where h is your height above sea level in metres.
Calculate the distance to the horizon if you were standing on a rocky headland 45 m above the sea below!

2. Originally Posted by Sazza
The Formula for calculating the distance (d) in kilometres to the horizon is:

d= 8 [that tick like symbol] h/5 where h is your height above sea level in metres.
Calculate the distance to the horizon if you were standing on a rocky headland 45 m above the sea below!
i don't know what think line symbol you are referring to

3. uh-hh on your calculator i think it's the symbol you use for square route!

4. Originally Posted by Sazza
uh-hh on your calculator i think it's the symbol you use for square route!
well then, couldn't you just say "square root" or better yet, "sqrt"?

is it $\displaystyle d = 8 \sqrt {\frac {h}{5}}$?

anyway, it doesn't matter what the formula looks like. just plug in 45 for h and solve for d

5. yer but i still do not see what i could use, to calculate that since the closest i can get to 8 is 45 divided by 5! how exactly do i do this? i haven't grasped what to do!

6. Originally Posted by Sazza
yer but i still do not see what i could use, to calculate that since the closest i can get to 8 is 45 divided by 5! how exactly do i do this? i haven't grasped what to do!
i cannot see why you have a problem with this, Sazza. haven't you worked with square roots before? of course, when they write the square root beside the 8 like that, they mean they are being multiplied.

$\displaystyle d = 8 \sqrt {\frac h5}$

when $\displaystyle h = 45$, we have:

$\displaystyle d = 8 \sqrt {\frac {45}5}$

$\displaystyle = 8 \sqrt {9}$

can you continue from here?