Splung.com Physics Forum Forum Index Splung.com Physics Forum
Discuss physics or ask questions. Part of the Splung.com physics web site.
 
   SearchSearch   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Egg Drop Catching Device

 
Post new topic   Reply to topic    Splung.com Physics Forum Forum Index -> Physics Help. Ask a Physics Expert
View previous topic :: View next topic  
Author Message
sarah



Joined: 13 Oct 2009
Posts: 1
Location: United States

PostPosted: Tue Nov 24, 2009 10:53 pm    Post subject: Egg Drop Catching Device Reply with quote

I need help with a project...I have to build a device using only paper, cardboard, and small amounts of tape that will catch an egg without breaking it. The device can only be 7cm high and 30 cm wide, and the egg is dropped from 1, 2, and 3m. We are learning about impulse now - I know I need to increase the duration of the impact.

A few people said I should just crumple up lots of pieces of paper and put that into a cardboard box - will that work?

Any other suggestions?
Back to top
View user's profile Send private message
hepcj
Site Admin


Joined: 23 Jun 2007
Posts: 123

PostPosted: Wed Nov 25, 2009 4:19 pm    Post subject: Reply with quote

Yes I think it will work provided the paper can deform enough to increase the time over which the momentum of the egg changes.

Impulse is the Force x time taken.

The falling egg has a certain momentum depending on the mass and the velocity.
To change that momentum requires a force. (Force is rate of change of momentum).

The average force on the egg will be
F = (momentum just before egg touches paper - 0)/time taken

When the egg falls it builds up a momentum and this will change from some value to 0. If it does this quickly then the average force on the egg is large and so it will break.
The scrunched up paper in the box will increase the time taken for the egg to slow down by deforming, absorbing the energy of the collision. If you slow the egg down over a long enough time it won't break.

Stunt men use cardboard boxes when jumping off high buildings to increase the time taken for them to change their momentum. I remember as a child making origami cubes out of paper and a layer or two of these in a box would also probably work.
Back to top
View user's profile Send private message Send e-mail
Display posts from previous:   
Post new topic   Reply to topic    Splung.com Physics Forum Forum Index -> Physics Help. Ask a Physics Expert All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


© Copyright 2010 Splung.com