Calculus Help needed

Soybomb

Diamond Member
Jun 30, 2000
9,506
2
81
Okay we've got a calc quiz on related rates tomorrow and I'm so completely lost I thought I'd ask and see if anyone can tell me how to this problem, if I can learn from that its at least a start hehe.

A man 6 feet fall walks at a rate of five feet per second away from a light that is 15 feet above the ground. When he is 10 feet away from the base of the light,
a.)at what rate is the tip of his shadow moving?
b.)at what rate is the length of his shadow changing?

If you have any insight as to the steps I should take to solve these I would be most appreciative. As a reminder this isn't homework but me studying so I hopefully don't flunk a quiz so don't feel like telling me how is wrong hehe.
Thanks!
 

Viper GTS

Lifer
Oct 13, 1999
38,107
433
136
First write an equation for his distance from the light. Then write an equation for the length of his shadow. Then relate the two, & solve for the length of his shadow. Plug in your variables for the answer to part A. Differentiate the equation, & then drop your variables in again to get the answer to part B.

At least that's how I remember it...

Viper GTS
 

flood

Diamond Member
Oct 17, 1999
4,213
0
76
Heres what you do-
Ever seen "Office Space"?
Well, you just dont go to clas anymore.
You dont drop the class.
You just dont go.
Same goes for the homework - you just dont do it anymore.
It worked for me! :)




For a while...
Still got an A out of it too!