Wa, if it were a 10-pound rock above water, should weigh roughly 6.6 pounds when submerged. Wa would weigh around 200 pounds underwater if it were a 300-pound boulder.
The weight of water is about 0.07 pound per cubic inch, so wa would be slightly lighter than water.
A person weighing 150 pounds would sink below the surface of the water if placed in completely dry sand. This is because the total weight of the person and the sand is more than what's allowed by law to be lost in an accidental drowning (138 pounds). However, if the person was immersed in water up to their neck, they would not drown even if they weighed all of their own body weight plus that of the sand (approximately 150 pounds).
In general, objects lose weight when submerged because some of the water molecules gain access to interior surfaces of the object causing it to shrink. Objects such as rocks, for example, lose volume as they shrink along with any gases inside them. For organic materials such as humans, this loss is equivalent to weight loss through dehydration.
Objects such as vehicles or buildings do not lose weight when submerged because any exposed surfaces remain wet even after exposure to air. Any weight lost during immersion is due to gas expansion or loss from within the object.
As a general rule, 66 equals a 2/3 ratio. In general, this indicates that Ww = 2/3 Wa.
However, there are exceptions to this rule. For example, if wa is very porous material such as sand or gravel, then it might not weight as much underwater because water can pass through it.
Another exception is if wa is composed of a dense material like concrete or granite. In this case, it would probably weigh about the same amount underwater as above water.
Finally, if wa is composed of a light material like wood or plastic, then it would likely weigh less underwater than expected due to its mass being concentrated into a small volume.
In conclusion, the weight of water is 887.5 grams per liter. If you were submerged in water, your weight would be reduced by about 66 percent.
How much weight does ten pounds have underwater? The average person weighs about 150 pounds, so the rock would be expected to weigh around 90 pounds.
The pressure of water is approximately 1 kilopascal (1 kPa) at 4 degrees Celsius (39.2 degrees Fahrenheit). So, if the rock was submerged in water at that temperature, it would weigh roughly 9 times as much as it does above water.
This means that one pound on dry land is supposed to be equal to 0.45 kg (0.99 lb) under water. However, due to air pressure adding to water pressure, one pound on dry land is actually expected to be slightly more than this value (about 1 kilopound or 0.984 kg).
So, the correct answer is 0.984 kg (or 1 kilopound).
Note that this value is close to the maximum load that can be carried by a single scuba diver. A total of two people could carry this amount of weight safely enough for their own use. Otherwise, they would need special equipment to support such a heavy load.
If it weighs more than this, then the rock is either not completely submerged or something else is weighing down on it.
If you try different rocks of equal size and weight but different shapes, you will find some that are less heavy when submerged. This happens because some of the weight of the rock is used for surface area instead of mass. For example, a ball-shaped rock will be less heavy than an egg-shaped one of the same size and material. The reason for this is that more of the surface area of the ball-shaped rock is exposed so more of its weight is used for buoyancy.
This is why a light ball is good for floating in water. It uses less energy to keep itself afloat because part of the weight is being carried by the water rather than the rock itself.
This loss can only occur if the water is present in sufficient quantity to cover the solid object completely.
If you're not sure where to start, start with 10% of your body weight. Subtract 4-6 pounds if diving in warm seas with a thin wetsuit, and add 4-6 pounds if diving in cold water with a lot of exposure protection.
For example, if you're 100 pounds (45 kg), you should weigh in at between 110 and 130 pounds (50 and 60 kg).
Divers who are over 130 pounds (60 kg) should wear one or two extra tanks. Those who are over 175 pounds (80 kg) should consider wearing a dry suit.
The percentage of weight you should carry depends on how deep you plan to go. If you're planning to dive only 20 feet (6 m), you can probably get by with 7%. More generally, 5% is a good rule of thumb.
Be careful not to exceed 10% of your body weight! That's when the risk of decompression sickness increases significantly.
Decompression schedules are based on how much time you spend at different pressures. The longer you stay at a given pressure, the more times you need to decompress before you can come back up to the surface.
Around 32 lbs. What is the weight of a dive helmet? Topside, a dive helmet weighs roughly 32 pounds, however underwater, the Archimedes Principle takes effect and it becomes neutrally buoyant. The mass of water it displaces is equal to its own weight.
The human body was not designed for aquatic life. Humans are born with lungs and heart designed for air, not water. Over time, these organs are altered by saltwater to some extent, but they can never be fully adapted to an aquatic lifestyle. To function properly, these organs need regular breaks from the water. Diving regularly allows them to recover from the stress of continuous use while enjoying the benefits of being submerged.
When diving, you should try to stay under water for as long as possible. This gives your body time to adapt to the pressure changes and allow your organs to rest between dives. However, if you have to resurface too soon after diving, you risk suffering the effects of decompression sickness (the "bends"). Decompression sickness occurs when gases that have dissolved in your fleshy tissues escape into your blood stream during the process of decompression. These gases can cause pain, redness, swelling, and even organ failure if not treated promptly.
Decompression schedules are guidelines only, as each person's tolerance to decompression stress is different.
When not in use, a diving tank may weigh anywhere from 26 to 40 pounds. Aluminum tanks weigh more, and steel tanks weigh less. A scuba tank, regardless of material, should feel mostly weightless when underwater. Only when it is seriously damaged can it no longer be returned to a shop for repair or replacement.
The inside of a scuba tank is almost completely hollow. It is made this way so that the interior volume is as large as possible without making the tank too thick. This allows more fish to be kept in a smaller space, which is important if you plan to dive many times per day.
Each time you ascend from a deep dive your body loses oxygen. The more often you dive, the faster you run out of breathable air. At some point you will need to come up for air unless you want to suffer consequences such as brain damage or death.
When you return to the surface each time you open your mouth to breathe, you consume more oxygen than you put into the atmosphere. This is why divers use spare sets of lungs called "decompression schedules" to ensure that they do not suffer harm due to dissolved gases in their blood. Decompression means "the process of removing gas bubbles from your body", and divers must go through this process before going back down again.