If the specific gravity has a value of greater than one, then the object sinks in water and if it is less than one, then the object floats in water. If the specific gravity has a value equal to one, then the object will neither sink nor float. The specific gravity is a very important factor in different industries.
On average, your mattress should last anywhere between 8 to 10 years. However, there are a lot of elements that can increase or decrease the longevity of your mattress. Your mattress is an investment â the better you take care of it and the more money you put into it will increase the longevity of your mattress.
All said and done it is best to change your mattress after a period of 7 years to get the best quality sleep. If you know how long does a memory foam last, you will know when to change it â so that you have no problems whatsoever. 1  Facebook. 2  Twitter. 3  Google+. 4  Pinterest. 5  LinkedIn.