Would the volume of water rise if ice melts in a cup of water?

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mc_watson87

The ice however is warmer than previous and its volume decreased.
And the increase in volume of water, but decrease in volume of ice (now water), should cancel one another out.

But the ice turns into water though, which would increase the level of water (due to that, that is).

Reply 21

mc_watson87

Invisible

But the ice turns into water though, which would increase the level of water (due to that, that is).

The ice, before melting, was already contributing to an increased water level, as it displaced water equal to its weight. Imagine removing the ice cube...the water level wud fall. Then imagine adding the water from the melted ice cube...the water wud have increased to the same level as it had been with the ice cube.

Basically the fact that the displacement of water is related to weight and not the volume of the ice cube tells us that the water level wud stay the same.

Reply 22

RobbieC

This is what it comes down to. If the 10% of ice that is not subermeged exceeds the volume of water gained when the ice melts, then the level will rise overall. This is because Ice has a small density than water (unlike with most solids, which is due to its unique Hydrogen bonding).

It all depends on how much MORE dense than ice water is, which I am sure is conveyed somewhere as a constant...

I could be wrong, but that seems logical to me.

Reply 23

john !!

I didn't know the ice displaced it's weight of water rather than volume. Kinda obvious now I've given it some thought

so the level will be the same
heh

Reply 24

RobbieC

mik1a

I didn't know the ice displaced it's weight of water rather than volume. Kinda obvious now I've given it some thought

so the level will be the same
heh

Weight is related to the volume. So what I suggested still applies, because the density of ice and water are different, so volume will also be different as weight remains constant...

Reply 25

Bezza

mik1a

I didn't know the ice displaced it's weight of water rather than volume. Kinda obvious now I've given it some thought

so the level will be the same
heh

This is true for anything that floats (or sinks for that matter) - the upthrust of the water is equal to the weight of the water displaced. It will float if its less dense than water (ie can displace the equivalent weight of water without being fully submerged) and sink otherwise.

Reply 26

danni_bella

Invisible had it going on :wink:

But I have another question: what about in the instance of the Titanic?

Reply 27

Barny

Bezza

The water level won't rise if an ice cube melts as the upthrust from the water is equivalent to the weight of water displaced (Archimedes I think) This is quite a popular principle for oxbridge physics/natsci interviews - my friend got asked about water level in a swimming pool if you took a brick out of your boat and threw it into the water (level goes down as in the boat it displaces volume of water with same weight as brick, in water it displaces water with same volume as brick)

I got asked this, only at a birmingham physics interview, not an oxbridge one!

He asked me loads of different version of it, he said a box, imagine its hollow, what will happen when I throw it off the boat? and then asked about it if its solid...and one other way but I cant remember now

Reply 28

gt@vetschool

2776

As per title. I have researched this, and have recieved many different answers, from quite a few sources. I want to hear your views and explainations for those views.