8 Grade Chemistry Help?!?
Archimedes' Principle of Buoyancy: The buoyant force of an object is equal to the weight of the fluid displaced, or pushed away, by the object...
Here's the question...
Use your understanding of Archimedes’ Principle to predict whether the following objects will float or sink in water.
Object A, with a mass of 15.7 grams that displaces 15.9 milliliters of water
Object B, with a mass of 4.2 grams that displaces 1.6 milliliters of water
Object C, with a mass of 9.4 grams that displaces 4.7 milliliters of water
Object D, with a mass of 11.4 grams that displaces 19.7 milliliters of water
And if you can explain it I would appreciate it!! Thank you!(:
Comments
The buoyant force of an object is actually the resistance offered by the fluid to the body.
This resisting force = weight of water displaced.
Now for Object A:
The weight of water displaced is more than the weight of the body. Therefore, the force offered by water is stronger than the weight/mass of the body which is a force that acts downwards, against the buoyancy. Hence, Object A will float.
Using this same idea,
Object B will sink since buoyant force is less than mass of body.
Object C will sink for the same reason.
While object D will float since buoyant force is much greater than weight/mass of the body. In fact Object D will be the most buoyant due to the large difference in weight of water displaced and mass of the body.
An object experiences a force upwards on it (upthrust) equal to the mass of water it displaces. But since water has density close to 1 then the volume of water displaced in ml is equal to its mass in g.
A
15.9g upthrust on an object of 15.7g means it will float.
B
1.6g upthrust on an object of 4.2g means it will sink.
Same method to answer the others.
thanks for the answers EVERYONE