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CAMBRIDGE SCIENCE CENTRE - HOW TALL IS MY TREE?
HOW T∆LL IS MY TREE?
M∆KE ∆ CLINOMETER TO FIND OUT...
A clinometer is a device that measures the angle of elevation. You can use this to measure the height of tall things that you can’t possibly reach the top of, like trees!
• A paper plate • A straw • Sticky tape • String • Blu tack • A helpful friend • A tree to measure • Measuring tape 1) Cut the paper plate in half and tape the straw along the cut edge. 2) Exactly halfway along the plate edge tape a piece of string with a lump of blu tack on the end, so that the string dangles beyond the edge of the plate. 3) Hold the plate horizontally and mark the 0° point on the plate, where the string and weight fall straight down. 4) Half way between the 0° point and the cut edge of the plate mark the 45° point (see the diagram).
45 O PAPER PLATE
0O PAPER STRAW
STRING AND WEIGHT 45 O
NOW, GR∆B ∆ FRIEND ∆ND FIND ∆ TREE TO ME∆SURE…
Look through the straw so that the top of the tree is visible.
Walk backwards and keep looking at the top of the tree through the straw.
Ask your friend to tell you when the string and weight line up with the 45° point on your clinometer.
On the ground, measure the distance you are from the tree.
To get an accurate measurement of the height of the tree, add this distance to your height.
45 O
0O
