Another "simple" physics question for ATOT

[ussfletcher]

Goes down if it hits the bottom, if it is hanging it will increase.

 

[TecHNooB]

Originally posted by: dighn

Originally posted by: TecHNooB
Depends on weight of the anchor. If the anchor weighs a lot, once overboard, the water level falls. If the anchor is very light, water level rises.

chances are the anchor is denser than water

anyway concur with m00. of course reality is a bit complicated. part ofthewegiht is still gonna drag on the ship but the loss of displacement from the weight difference should still trump the gain in displalcement from the anchor. steel (?) is a lot denser than water.

The idea is that if the anchor is very dense, the boat displaces more water. If you have a very tiny, dense anchor, more water is displaced when the anchor stays on the boat. However, if you have a very massive anchor with little density (but still denser than water), more water is displaced when anchor is thrown overboard.

 

[TallBill]

Originally posted by: TecHNooB

Originally posted by: TallBill

Originally posted by: TecHNooB
Density on weight of the anchor. If the density weighs a density, once overboard, the water level falls. Density the anchor is very light, water density rises.

Has nothing to do with the weight.

Replace some words with density then

Hmm, still doesn't work

 

[Fenixgoon]

the water level lowers beer: to Mooo)

when held on the boat, the anchor is displacing its weight in water.
when in the water, the anchor displaces its volume in water, which is less than its own weight (since the density of steel > water)

therefore, the water level indeed drops

 

[eLiu]

Originally posted by: Fenixgoon
the water level lowers beer: to Mooo)

when held on the boat, the anchor is displacing its weight in water.
when in the water, the anchor displaces its volume in water, which is less than its own weight (since the density of steel > water)

therefore, the water level indeed drops

AHHH A COW CONSPIRACY

edit: also, nice question. my knee jerk reaction tricked me at first, haha.

 

[octopus41092]

Originally posted by: Mo0o
Water drops

In the boat, the anchor is displacing its weight in water.
In the water, the anchor is displacing its volume in water.

But since the anchor is denser than water, its weight in vol of water is greater than its volume in water. Thus when u toss that mofo into teh water, the water drops

This

 

[JTsyo]

Originally posted by: Fenixgoon
the water level lowers beer: to Mooo)

when held on the boat, the anchor is displacing its weight in water.
when in the water, the anchor displaces its volume in water, which is less than its own weight (since the density of steel > water)

therefore, the water level indeed drops

I guess this assumes the anchor is not attached to ship when it's dropped right? Otherwise the chain would exert a force difference on the ship.

 

[darkxshade]

Doesn't it depend if the anchor is touching the ground?

Because if it isn't... doesn't it mean the anchor is displacing both its weight and volume in the water by both dragging the boat down with its weight + its own volume?

 

[Fenixgoon]

Originally posted by: darkxshade
Doesn't it depend if the anchor is touching the ground?

Because if it isn't... doesn't it mean the anchor is displacing both its weight and volume in the water by both dragging the boat down with its weight + its own volume?

if the anchor weren't touching the ground, then it would only be displacing its volume in water. the appropriate force balance is:

the tension in the chain + buoyant force = weight of anchor

tension in chain = apparent weight = weight of anchor - buoyant force

also knows as archimedes' principle, which is frequently used for finding the densities of objects

 

[mesthead21]

This question would be a lot better if it were a plane on a treadmill

 

[Mo0o]

Originally posted by: TecHNooB

Originally posted by: dighn

Originally posted by: TecHNooB
Depends on weight of the anchor. If the anchor weighs a lot, once overboard, the water level falls. If the anchor is very light, water level rises.

chances are the anchor is denser than water

anyway concur with m00. of course reality is a bit complicated. part ofthewegiht is still gonna drag on the ship but the loss of displacement from the weight difference should still trump the gain in displalcement from the anchor. steel (?) is a lot denser than water.

The idea is that if the anchor is very dense, the boat displaces more water. If you have a very tiny, dense anchor, more water is displaced when the anchor stays on the boat. However, if you have a very massive anchor with little density (but still denser than water), more water is displaced when anchor is thrown overboard.

I think as long as the anchor is denser the water will drop no matter what

 

[slackwarelinux]

assuming the anchor hits bottom, or detaches from the ship:
neffing on atot instead of studying for my fluids and thermal final in a few hours:

on the boat (assuming it isn't sinking):
mass * gravity = pwater * gravity * vdisplaced
mass = pwater * vdisplaced

delta m / pwater = delta vdisplaced
panchor * vanchor / pwater = delta vdisplaced (decrease in sea level)

then the anchor takes up (assuming denser than water)
vanchor = delta vdisplaced (increase in sea level)

so,
the change in sea level would be
((vanchor) - ( panchor * vanchor / pwater )) / (surface area of sea)

where vanchor is volume, pwater is the density of water, and panchor is the density of the anchor
this means the sea level would decrease as long as panchor > pwater

 

[darkxshade]

Originally posted by: Fenixgoon

Originally posted by: darkxshade
Doesn't it depend if the anchor is touching the ground?

Because if it isn't... doesn't it mean the anchor is displacing both its weight and volume in the water by both dragging the boat down with its weight + its own volume?

if the anchor weren't touching the ground, then it would only be displacing its volume in water. the appropriate force balance is:

the tension in the chain + buoyant force = weight of anchor

tension in chain = apparent weight = weight of anchor - buoyant force

also knows as archimedes' principle, which is frequently used for finding the densities of objects

Explain/clarify?

If the anchor is not chained and thrown overboard, the boat rises which more than offsets the volume of the anchor = drop in sea level

If the anchor is chained, thrown overboard and not touching ground. The boat doesn't rise + volume in water = increase in sea level? Whether the anchor is in the boat or not, the total weight of the boat + anchor doesn't change until the anchor hits the ground.

edit: This is assuming the chain isn't long enough for the anchor to reach the bottom because I know once the anchor is thrown overboard, the sea level drops temporarily as the anchor sinks(weight not being displaced = boat rises for a while) but once the chain is slack, the anchor imparts its weight back onto the boat which pulls it down.

 

[So]

Originally posted by: Mo0o
Water drops

In the boat, the anchor is displacing its weight in water.
In the water, the anchor is displacing its volume in water.

But since the anchor is denser than water, its weight in vol of water is greater than its volume in water. Thus when u toss that mofo into teh water, the water drops