- #1
BOAS
- 553
- 19
Hello,
i'm struggling to understand the equation I've been given for finding the radius of a sphere by using a spherometer. I wasn't sure if this would be better in the physics section, but I figured it is essentially geometry.
"From the diagram, simple geometry shows that the radius, r may be calculated from the formula [itex]r = \frac{h^{2} + l^{2}}{2h}[/itex]"
See attached for the diagram.
The [itex]h^{2} + l^{2}[/itex] term makes me think that the curved surface is being approximated as the hypotenuse of a right angled triangle, but I can't make sense of where dividing by [itex]2h[/itex] gets you.
I've been trying to relate it to the formula for the radius of a circle using an arc, but I'm npt getting anywhere.
Please can you help?
Thanks!
i'm struggling to understand the equation I've been given for finding the radius of a sphere by using a spherometer. I wasn't sure if this would be better in the physics section, but I figured it is essentially geometry.
Homework Statement
"From the diagram, simple geometry shows that the radius, r may be calculated from the formula [itex]r = \frac{h^{2} + l^{2}}{2h}[/itex]"
See attached for the diagram.
The Attempt at a Solution
The [itex]h^{2} + l^{2}[/itex] term makes me think that the curved surface is being approximated as the hypotenuse of a right angled triangle, but I can't make sense of where dividing by [itex]2h[/itex] gets you.
I've been trying to relate it to the formula for the radius of a circle using an arc, but I'm npt getting anywhere.
Please can you help?
Thanks!