James’ Watts GroupMember 1) Yeap Jia Hung2) Wong Lee Lung3) Aileen Wong

Cartesian Diver

(Archimedes Principle)

List Of Material

500 ml bottle water

A Packet of Ketchup

A Jug

Warm water

Arrangement of model

Ketchup packt

Warm water

Bottle

1.The water is poured into the bottle by using a jug

Procedure

2.The water is poured almost full

3.The ketchup packet is putted into the bottle

4.Water are added into the bottle until it is fully full

5.The top of the bottle were screw hard

6.The bottle were squeezed and the movement of the ketchup packet is observed.

7.The bottle is stopped from squeezed and the movement of ketchup packet is observed

Observation

The ketchup packet sinks when the bottle is squeezed and rises when the bottle were stopped squeezed.

Whether an object sinks or floats depends on if the total weight of the object is greater or less than the weight of the water it displace.when a packet is just barely less dense than water are barely canceling the parts that are more dense than water(package and ketchup).The cartesian diver worksBecause the pressure exert on bottle is transefered to air bubble within the packet,making it smaller,thus increasing its density.as this occur ,the packet sinks as the air no longer cancels the ketchup.when you release the pressure ,the bubble expands again,and the packet rises.Fish have an air sac within their bodies,and by controlling the amount of air in the sac,they use the same principle to rise and sink.Also according to pascal law,pressure in a fluid is exerted equally throughout the fluid.no matter where u squeeze the bottle,at the top or at the bottom,the pressure will be exerted equally and the same diving effect will occur,The same principle is at work in diver’ s bouyancy compesation device(BC)or even your lungs at depth underwater.Release air from the BC (or ur lung),it will compress the remaining volume,and u sink.Add some volume(by adding more air to your BC or ur lungs,and you will rise to the surface,mastering these two skills are the ABC’s of diving

Discussion

ConclusionThis activity demonstrates the property of bouyancy.An object is buoyant in water due to the amount of water it displaces. The pressure that exert on bottle is transefered to air bubble within the packet,making it smaller,thus increasing its density.as this occur ,the packet sinks as the air no longer cancels the ketchup.when you release the pressure ,the bubble expands again,and the packet rises.

Bibliography

1. Foo Seng Teek,Yee Cheng Teik,Chong Geok Chuan,Lee Beng Hin,

Success Physics SPM,Selangor,Oxford Fajar Sdn.Bhd.2oo72. www.wikihow.com/make-a-Cartesian-diver-with-a -

ketchup packet