- #1

Cake

- 100

- 16

## Homework Statement

An elevator rises at a constant velocity. A marble is dropped from a hole in the elevator at time [itex]T_1[/itex]. It accelerates downward at 9.8 m/s^2 and hits the floor at time [itex]T_2[/itex]. Define the height at time [itex]T_1[/itex]

## Homework Equations

[itex]y=y_0+v_0 t-1/2gt^2[/itex]

## The Attempt at a Solution

So this sounds easy as cake. The initial velocity is 0 and we can assume [itex]T_1[/itex] is 0. Ok, so I can define the function of position as:

[itex]y=y_0-4.9t^2[/itex] which at time [itex]T_2[/itex] equals 0.

so

[itex]y_0=4.9(T_2)^2[/itex]

Sound reasonable?

But for some reason the hint in the back of the book is this example of what the answer is supposed to look like. It says:

[itex]T_1=T_2=4[/itex] then [itex]y_0=39.2[/itex]

Which doesn't line up with my equation that I've used to determine the height. So idk. What did I do wrong?