A tree casts a shadow that measures 5 m. At the same time, a meter stick casts a shadow that is 0.4 m log. How tall is the tree?
2006-11-22 15:00:29 · 12 answers · asked by msgoldie720 2 in Science & Mathematics ➔ Mathematics
1m/0.4m = x/5m
0.4x = 5
x = 12.5
2006-11-22 15:03:15 · answer #1 · answered by bgdddymtty 3 · 0⤊ 1⤋
Consider first the meter stick.
The meter stick is, of course, 1 meter long and is perpendicular to its 0.4 meter long shadow that is casted on the ground. Imagine a line joining the top of the meter stick to the far end of the shadow. The angle between this line and the shadow would be:
tan x = height of meter stick / length of shadow
tan x = 1 m / 0.4 m
x = 68.1986 degrees
This would be the same angle that the tree's shadow and a line joining the top of the tree to the far end of its shadow would be making. So:
tan x = height of tree / length of shadow
tan (68.1986 degrees) = height of tree / (5 meters)
height of tree = 12.5 meters
2006-11-22 15:20:31 · answer #2 · answered by Askhole Ninja 3 · 0⤊ 0⤋
The ratio of the shadow to the height of the object is the same for both the tree and the meter stick
height_of_meter_stick / meter_shadow = height_of_tree / tree_shadow.
1 meter / 0.4 meter = height_of_tree / 5 meter
5/0.4 = height_of_tree
height_of_tree = 12.5 meters
2006-11-22 15:06:09 · answer #3 · answered by anonymous 2 · 0⤊ 0⤋
given:shadow of the tree=5m.
shadow of meter scale=0.4m
as per question the ratios of the heights of the meter scale with respect to the tree is constant
therefore:let the height of the tree be=x:
so, x/5=1/0.4
0.4x=5
x=5/0.4
x=12.5
Therefore height of the tree=12.5 meters.
2006-11-22 15:13:08 · answer #4 · answered by manu 2 · 0⤊ 1⤋
ratios, fractions, call it what you will
meter stick / .4 meter shadow = tree hight in meters/5 meter shadow.
multiply by 5 meters on both sides
5 meter/.4 meter = tree hight in meters * 5/5 meter shadow
5/.4meters=tree hight in meters.
I hope you can do the last step
2006-11-22 15:32:38 · answer #5 · answered by Anonymous · 0⤊ 0⤋
You would use ratios.
5m : tree height = .4 m : 1 m
5 / .4= tree height= 12.5
2006-11-22 15:10:27 · answer #6 · answered by Mei 2 · 0⤊ 0⤋
x = height of tree
x / 5 = 1 / 0.4 --- Divide 1 by 0.4
x / 5 = 2.5 --- Multiply both sides by 5
x = 12.5 meters
2006-11-22 15:05:50 · answer #7 · answered by Anonymous · 0⤊ 1⤋
i think you need to divide 5 by 0.4 to find the answer
2006-11-22 15:08:42 · answer #8 · answered by ..... 2 · 0⤊ 0⤋
tree legnth = 5 / 0.4 = 12.5m
2006-11-22 15:09:14 · answer #9 · answered by M. Abuhelwa 5 · 0⤊ 0⤋
you need to figure it out on your own instead of wanting other people to do it for you.
2006-11-22 15:08:57 · answer #10 · answered by Lucille 3 · 0⤊ 0⤋