- #1

- 26

- 0

## Homework Statement

Houdini is in a giant flask and he stands on a block where his feet are shackled and you need to calculate some vital information to help him out.

Cross section of flask = r(h)=10/(sqrt(h+1))

water is being pumped into the flask at 22pi

Takes Houdini 10 mins to escape

Ignore blocks volume and his volume

He's 6ft tall

1) You first task is to find out high the block should be so that the water reaches the top of his head at the 10 min mark. Express the water in the flask as a function of the height of the liquid above ground level. I calculated this to be approximately 2ft.

220pi=100pi(ln(h+1))

h≈8ft

2) Let h(t) be the height of the water above ground level at time t. In order to check the progress of his escape moment by moment, Houdini derived the equation for the rate of change dh/dt as a function of h(t) itself. Derive this equation. How fast is the water level changing when the flask first starts to fill? How fast is it changing when the water just reaches the top of Houdini's Head? Express h(t) as a function of time.

## Homework Equations

v=100pi(ln(h+1))

dv/dt=100pi((h'+1)/(h+1))

## The Attempt at a Solution

solve for h'? h'=.22(h+1) - 1

integrate this?

Last edited: