Wednesday, May 12, 2010

NEW PLAN ...

So i have to change my idea for my SRP and I'm so sorry ms Zhang that i haven't posted this earlier to inform you.

I'm still undecided on what topics to do though and these are the few ideas that I'm still tossing between.

1. How does the shape of an object affect its ability to float .

Various objects sink or float in water. Whether an objects sinks or floats in a liquid depends mainly on two factors: density and buoyancy.

Density is the measure of the relative "heaviness" of objects with a constant volume.

Buoyancy is an upward acting force, caused by fluid pressure, that keeps things afloat.

So how do these factors relate .

The more denser an object the less buoyancy.











(DrStrong) They are related through Archimedes' principle,

FB = ρgV

where FB is the buoyancy force, ρ is the density of the liquid, g is gravity, V is the volume of water displaced by the object (in other words, the volume of the object that lies underneath the water surface).

If FB is greater than the weight of the object, the object will float upwards. If not, the object will sink downwards.

So, the denser the liquid, the GREATER the buoyancy. However, the greater the object weight, the less the buoyancy. Another way to look at it is that the object itself has a volume and density, the product of which is the weight. So if a totally submerged object has less density than the liquid, it will be buoyant. If it has greater density than the liquid, it will sink.



In my experiment i will carry out a simple test to see what affects a object to float or sink.

Objects with the same mass will be put in water. Each object will have a different shape ; large flat piece of slate, small piece of slate, large ball, small ball , etc.

This will determine whether or not the surface area affects the objects buoyancy .

Objects with different masses but same surface area properties will then be tested to determine if the density of an object will affect its buoyancy.



2.
what type of washing detergent is best at removing stains

Lauddry detergent typically consists of ionic and anionic surfactant which act as the detergent to remove the dirt from the clothes, perfume, phosphors aticaking agents to prevent the powder becoming one large lump in the prescence of moisture. Biological laundry detergents contain enzymes which act as catysts to "eat" the dirt off of the laundry. Detergents may have other additives such as bleaches and fabric softeners.

In my experiment, i will determine which brand of detergent works best on removing stains. Cloths with dirt and other satins with remains soaked in a container with detergent and water. The cloth with the less dirt is determined as the best detergent.

The variables that are to be controlled are : the amount detergent, the type of cloth and the amount of dirt on the cloths .




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