$32,000 for Married Filing Jointly. $0 for Married Filing Separately if the spouses lived together during the year. If your total income is more than the base amount, you might owe some tax on your Social Security benefits.
Pure water at 60F has about 27.78 inches of water column (INWC or INWG) per psi or approximately 0.43197 psi/ft. This is from memory; but it should be close. Fresh water: 0.43 psi per foot Sea water: 0.44 psi per foot. So, for each additional 10 feet of depth, figure about 4.3 to 4.4 psi increase in pressure. You can calculate this yourself by using the fact that fresh water weighs about 62.4 pounds per cubic foot (pcf) and sea water weighs about 64 pcf.
4000 psi, 3500 psi and 3000 psi all refer to the compression strength of the concrete (resistance to downward force in pounds per square inch), usually at 28 days of curing. Ready-mix suppliers sell their concrete based on itâs rated psi and the higher the psi, the more it will cost. In general, 3000 psi is usually used for concrete walls and footings and 3500 psi is used for flat work such as floors and walkways. However, a good contractor who wants to avoid call-backs will use at least a 4000 psi mix for a driveway.