Question about Specific Gravity.

In summary, specific gravity is the ratio of an object's density to the density of water. If the specific gravity is less than 1, the object will float. If it is greater than 1, the object will sink. If the specific gravity is equal to 1, the object will stay at whatever depth it is placed as long as it is completely immersed in water. This is because the buoyant force from the water pushing up on the object will cancel out with the object's weight, resulting in no net force. However, the density of water can vary slightly with temperature and pressure, so knowing the standard conditions is important for precise calculations.
  • #1
Suarden
19
0
I know that if the specific gravity is less than 1, it will float and if it is greater than 1 it will sink. Now here's the question, if the specific gravity is equal to 1, what will happen? Please I need your explanations. Thank you so much!
 
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  • #2
The object will stay at whatever depth it's placed - as long as it's totally immersed - because the upthrust is equal to the weight (no net force). If some of it is above the surface, it will sink (and then continue moving downwards until the Kinetic Energy is dispersed due to drag).
 
  • #3
So, the specific gravity of a thing is the ratio of the density of that thing over the density of water.

The buoyant force from water is equal to the weight of the displaced water.
If the density of your object is the same as the surrounding water, then the buoyant force of the water pushing on the object will cancel with the weight of the object, giving you no net force.

In this case, (as has been said) the object will stay put wherever underwater you place it.

However, the density of water is not contant, it changes (very slightly) with temperature and pressure.

In order to be exactly certain that the net force will be precisely zero, one needs to know the standard temperature and pressure the specific gravity is based on. Wikipedia has an excellent article on the subject.
http://en.wikipedia.org/wiki/Specific_gravity
 

1. What is specific gravity?

Specific gravity is a measurement of the density of a substance compared to the density of water. It is a unitless quantity and is typically denoted as "SG" or "s.g.".

2. How is specific gravity measured?

Specific gravity is measured by comparing the weight of a substance to the weight of an equal volume of water. This is typically done using a device called a hydrometer.

3. What is the significance of specific gravity in science?

Specific gravity is important in science because it can be used to identify substances and determine their purity. It is also used in various industries, such as brewing and winemaking, to measure the concentration of solutions.

4. How is specific gravity related to density?

Density and specific gravity are closely related. Density is a measure of how much mass is contained in a given volume of a substance, while specific gravity compares the density of a substance to the density of water.

5. What factors can affect the specific gravity of a substance?

The specific gravity of a substance can be affected by factors such as temperature, pressure, and the presence of impurities. It can also vary depending on the type of substance being measured.

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