Egg floating in salt water - Science experiment
This is an experiment to understand the concepts of density and buoyant force for students.
For this experiment you'll need:
• Some eggs
• Water
• Salt
• A tall measuring glass
Pour some water into the measuring glass until it is about half full. Take an egg and gently put into the glass. What did u observe? The egg sinks. It dives to the bottom of the glass.
Pour some fresh water into a measuring glass. Now, add lots of salt to this glass of water. You might need to add atleast 6 table spoons of salt to make the water salty.
Now, take the egg and gently lower the egg into the salt water and watch what happens. The egg floats.
Try to push down in the water. Its does not sink and continues to float. Repeat this experiment with another egg.
Now let's understand what just happened here:
An egg sinks in salt water as salt is denser as compared to fresh water. For any object to float, the weight of the object should be lesser than or equal to the buoyant force. Buoyancy or buoyant force is an upward force exerted by a fluid that opposes the weight of an immersed object.
The weight of the water displaced = Density of the water * Volume * Gravity
Obviously, since the density of salt water is more than density of fresh water, hence the weight of the water displaced will be greater in the case of the salt water, resulting in a greater buoyant force. This greater buoyancy opposes the weight of the egg and hence stops it from sinking.
Infact, the more salt in the water, the more buoyant an object becomes. In this case, the density of the salt water is greater than the density of the egg. Adding the salt in the water increased the density of the water there by causing the eggs to float.
Do try this experiment at home or at school with your friends and let us know how you enjoyed floating eggs :)
6 мар 2013
