Solving the Watermelon Drop Physics Problem: Step-by-Step Guide

[Alanf718]

Ok Iam having problems again with yet something else.

The problem states that

A physics student with too much free time drops a water melon from the roof of a building. He hears the sound of the watermelon going splat 2.50s later. How high is the building? The speed of sound is 340m/s. You may Ignore air restiance.

Well I tried solving this by replacing t by

t= 2.5 - (deltaY/340);

but the book tells me a completely different answer. Can anyone show me how to do this one?

 

[Galileo]

The time it takes until you hear the sound from the moment it is dropped is the times it takes the melon to fall to the ground plus the time it takes for sound to go from the ground to the top of the building.
Write down the equation for this and solve for the height.

 

[Alanf718]

thats what i did with
t= 2.5 - (deltaY/340);

but I don't get the right answer

 

[Galileo]

Why don't you elaborate on what you've done?
What method did you use exactly. You replaced t by 2.5 - (deltaY/340) in what equation? What answer did you get?

Try giving an expression for the amount of time it takes for the melon to drop to the ground. Then for the amount of time it takes for sound to travel up the length of the building.