2007-01-24 02:36:39 · 20 answers · asked by Basement Bob 6 in Science & Mathematics ➔ Other - Science
The cannonball in the boat displaces an amount of water equal to the MASS of the cannonball. The cannonball in the water displaces an amount of water equal to the VOLUME of the cannonball. Water is unable to support the level of salinity it would take to make it as dense as a cannonball, so the first amount is definitely more than the second amount, and the water level drops.
2007-01-25 01:41:11 · update #1
The water level will go down.
An object floating in water displaces a volume of water equal to its weight. So a 200 pound boat displaces 200 pounds of water, and the water level rises as if you added 200 pounds of water. Add a 12-pound cannonball to the boat and it displaces another 12 pounds of water. But throw the cannonball overboard and it only displaces its volume in water. Since iron is nearly 8 times as dense as water, the cannonball now only displaces about a pound and a half of water. So the water level falls. (By an insignificant amount, unless you're in a very small tank, of course.)
2007-01-24 05:46:33 · answer #1 · answered by injanier 7 · 2⤊ 0⤋
Wow. Eugene, injanier, and KrazyKyng were the only ones with the right answer. Everybody else got this wrong.
The correct answer is: The water level will go down a slight amount.
When something floats, it displaces its *weight* in water. When it sinks it displaces its *volume* in water.
So when a cannonball is in the boat, it is adding to the weight of the floating boat, and so it displaces its weight in water. If you hold it over the water and let go, at that moment it is no longer contributing weight to the boat, so the boat rises, and the water level drops a slight amount. But when the cannonball hits the water and sinks it displaces its volume, so the water rises a slight bit.
Since a cannonball is more dense than the water, its equivalent weight in water exceeds its equivalent volume in water (we know this because it sinks). So the amount the water level drops (its weight in water) is more than the amount it rises (its volume in water). So the water level drops.
2007-01-24 07:35:53 · answer #2 · answered by secretsauce 7 · 1⤊ 0⤋
If you were standing on a dock, and dropped it in, the water level change would be so insignificant that it is impossible to measure. Dropping it from the boat would be even less, since the pressure applied by the boat is related to the mass of the cannonball, there is already some displacement occuring, if this were in a small tub, there would be a measureable amount of displacement though.
2007-01-24 02:43:03 · answer #3 · answered by poseidenneptune 5 · 1⤊ 1⤋
Yes. While the ball is on board the boat, there will be a displacement of water equal to its own weight. When dropped overboard the displacement it will replace its own volume. It takes more water to equal its weight than its own volume, since it is heavier than water. So the level will decrease slightly.
2007-01-24 07:25:27 · answer #4 · answered by Anonymous · 2⤊ 0⤋
Yes it would but not hardly noticeable because when you are on the boat the balls weight pushes down on the boat, displacing water. When the ball is in the water it's the mass displacing the water not the weight.
2007-01-24 02:57:24 · answer #5 · answered by Zephos 1 · 1⤊ 1⤋
Of course. Since the ball was floating and in the boat, the boat was initially displacing the weight of the cannon ball. When the ball drops into the water, it sinks and not as much water is being displaced. The water level goes down.
2007-01-24 02:41:18 · answer #6 · answered by Gene 7 · 3⤊ 2⤋
No, but if ice cubes in a glass melt (as per the North pole) the water level goes down.
If the entire S. pole melts the ice surrounding the land that is supported by and is displacing water will melt first giving us more land world wide, as all of it melts it will become some v. expensive real estate! Unfortunately we will most likely be on a new 10 thousand year natural cycle by then and serious eco warriors will either be extinct or wearing each others bones through their noses!
2007-01-24 02:46:47 · answer #7 · answered by Anonymous · 2⤊ 2⤋
No. The cannon ball was already on the boat and therefor its dispersion was already reflected by the water. If your talking lon term though then yes because the boat can always be taken out of the water and I doubt anyone is gonna dive down and get the cannon ball.
2007-01-24 02:40:50 · answer #8 · answered by mjobrien10 3 · 2⤊ 2⤋
yes, but the amount depends on the size of the water. If it's a bathtub, a lot. If it's the ocean, neglible.
Oh wait....I think Kuteky is right.
2007-01-24 02:39:52 · answer #9 · answered by jfahd 4 · 1⤊ 1⤋
No because there was pressure on top of the water making the water level higher. He just changed the sapce.
2007-01-24 02:39:59 · answer #10 · answered by *Aimzie* 3 · 1⤊ 2⤋