why do objects float in salt water

Do Objects Float Better in Salt Water Than in Fresh Water? If you've ever floated in the ocean, you may have noticed that it's much easier to do so than it is to keep afloat in a swimming pool. If you had to guess why that's the case, what would you say? The answer is just one word salt. When salt is dissolved in water, as it is in ocean water, that dissolved salt adds to the mass of the water and makes the water
denser than it would be without salt. Because objects float better on a dense surface, they float better on salt water than fresh water. The denser the salt water, the easier it is for objects to float on top of it. You could make a science fair project out of this concept by measuring different amounts of salt into a specific amount of water and testing how well different objects float.

A suggested method is to use five containers that are all the same size and shape. Put the same amount of water into each container. Use the first container as your control, and do not add any salt to it. Add 1 teaspoon of salt to the second container, two teaspoons to the third container, and so on. Locate some objects that barely float in water, such as a paper clip, a small plastic ball, and a pen. Place the objects, one at a time, in the first container and observe how long they float in the water. Dry off each object and place it into the other containers in -the same manner, observing carefully how long they remain afloat in the water.

Run three trials for each object in each container, recording all your information carefully and then graphing it. There are hundreds of science fair projects dealing with physical science topics. Use your imagination to try to think of others you may enjoy doing. Many people donвt see floatation therapy as a health option because they fear drowning in the floatation capsule. Since floatation therapy can be conducted in salt water, candidates have less to fear than they think. Today, weвll examine the science of salt water and buoyancy in an attempt to allay candidatesв concerns. Density The main reason objects float more easily in salt than fresh water is their density.

Density is the measurement of a materialвs mass per unit of volume. Freshwater has a normal density of about one gram per cubic centimeter. Low density makes it more difficult for objects and people to float. Salt increases waterвs density by changing its mass without significantly changing its volume. With enough salt in the water, a person will become buoyant and float. This is true for objects as well, like a floatation capsule, for instance. If youвre new to floatation therapy, you can familiarize yourself with the science behind density with some home experiments. For example, remove an egg from your fridge and let it warm to room temperature. Then prepare five containers, one of plain tap water and four with varying degrees of salt stirred in (not all salt will dissolve).

Itвs a good idea to add salt sequentially в two teaspoons to cup number two and so forth. The more salt in the container, the faster and higher your egg will float. Salt and the Floatation Process Most floatation therapies use Epsom salts because of its health benefits, including the ability to replenish magnesium. Epsom salts allow the candidate to float with his or her face out of the water. This helps people who are skittish about water or drowning feel more comfortable and in control of their bodies. Most floatation spas use about a thousand pounds of Epsom salts in each tank, so candidates can float no matter their weight or height.

Acclimating to Salt in the Floatation Process The goal of floatation therapy is sustained sensory deprivation. The salt solution in the water may disrupt this for some people, so be prepared to acclimate. Do not shave or wax before floatation therapy since the salt can irritate your skin and make it more difficult for you to relax. Cover any open wounds. Again, skipping this step will hinder the sensory deprivation process and may also let harmful bacteria into the floatation tank. Do not drink alcohol or indulge in heavy caffeine before an appointment. Both alcohol and caffeine may react with the salt and make you feel tense, afraid, or out of control.