- #1
Saladsamurai
- 3,020
- 7
Homework Statement
A light shines from the top of a pole 50 ft high. A ball is dropped from the same height at a point 30 ft away. (see thumbnail). How fast is the shadow of the ball moving along the ground .5 seconds later assuming ball falls a distance of [tex] s=16t^2[/tex]
Homework Equations
Chain Rule/ Implicit Differentiation
The Attempt at a Solution
I have labeled the height of the ball after 1/2 second as [tex]h=50-16t^2[/tex] which=46.
I have assumed (possibly incorrectly) that the base of the triangle larger is [tex]x[/tex] and the smaller base is [tex]x-30[/tex].
I calculate [tex]\frac{dh}{dt}=-32t\left|_t_=_.5=-16[/tex]
I know that[tex] \frac{dx}{dt}=\frac{dh}{dt}*\frac{dx}{dh}[/tex] ...but I am having trouble writing x as a function of h.
I think it has to do with similar triangles. But I can't seem to make it work.