# Two cups are filled with the same level of Water - one has ice cubes.

• dnkim64
In summary: You could then use that insight to answer the question correctly.If you just say "there's not enough information" you're basically saying "I'm not going to think about it unless you hold my hand and tell me exactly what to do." I think that's a bad attitude to take. The world is full of ambiguity and you're going to have to face it.
dnkim64

## Homework Statement

Two cups are filled to the same level with water. One of the two cups has ice cubes floating in it. When the ice cubes melt, which cup has the higher level of water?
1. Same for both
2. Cup with ice cubes
3. Cup without ice cubs

## The Attempt at a Solution

I thought it was the 2. Cup with ice cubs.

Actual answer is 1. Same for both.

My Dilema: The question does not specify which came first - the water or the ice cubes.
If the cups were filled to the same level and THEN the ice cubes were added, then the cup with ice cubes would have a higher level. Essentially adding "more water" in the form of ice cubes.
Vice versa, if the ice cubes were orignially in the cup, and THEN both cups filled to the same level, then yes - they'd be the same level of water after melting.

Can anyone validate my claim that this question does not provide enough information? Or am I simply daft

You have found an ambiguity in the letter of the question.

One interpretation of the question results in a trivial problem with a trivial answer. (A six year could say that the one that's had something dropped into it after the water levels were balanced will have a higher water level.)

The other interpretation results in a problem that requires you to think about the physics of density and buoyancy and what happens to the water level when the ice melts. i.e. the stuff you're studying.

Your education as designed to help you not merely find answers to problems, but to also correctly interpret what the problem is you're trying solve.

i.e. your exploitation of an ambiguity such as this will not fly in the real world. You will be expected to demonstrate "common sense".

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Hi dnkim64! http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif

dnkim64 said:
Two cups are filled to the same level with water. One of the two cups has ice cubes floating in it. When the ice cubes melt, which cup has the higher level of water?
1. Same for both
2. Cup with ice cubes
3. Cup without ice cubs
Maybe it should be worded simply: Two cups are filled to the same level.

We know what is meant, this is not a new question.

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One of the things that the problem would (or SHOULD if properly worded) have you think about is this:

Which has the greater volume, an ice cube or the water that exists when it melts.

right now?

Your claim is valid. The question does not provide enough information to determine which cup will have a higher level of water after the ice cubes melt. It could be either cup, depending on the sequence of events. As a scientist, it is important to always consider all possible variables and factors when making conclusions. In this case, the lack of information makes it impossible to reach a definitive answer. It would be beneficial to clarify the question by specifying the order in which the water and ice cubes were added to the cups.

## 1. How does the presence of ice cubes affect the water level in a cup?

The presence of ice cubes does not affect the water level in a cup. The ice cubes displace a certain volume of water, but when they melt, they will turn back into the same volume of water, maintaining the original water level.

## 2. Is the temperature of the water in both cups the same?

No, the temperature of the water in the cup with ice cubes will be lower due to the melting ice cubes. The melting process requires energy, which is taken from the surrounding water, causing it to cool down.

## 3. How long will it take for the ice cubes to melt completely?

The time it takes for the ice cubes to melt completely depends on various factors such as the size of the ice cubes, the temperature of the room, and the material of the cup. Generally, it can take anywhere from a few minutes to half an hour.

## 4. Why does the cup with ice cubes feel colder to touch?

The cup with ice cubes feels colder to touch because the ice cubes are absorbing the heat from your hand, causing your hand to feel cooler. This is due to the second law of thermodynamics, which states that heat always flows from a warmer object to a cooler one.

## 5. What happens to the water level when the ice cubes melt?

As the ice cubes melt, the water level will remain the same. The volume of water displaced by the ice cubes is equal to the volume of water produced by melting, so the total water level will not change.

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