Category: physics

Last Problem:

Two glasses filled with water are balanced on a scale. What happens to the scale when you stick your finger in one of the glasses? Will that side of the balance tip as it it were heavier?

How would the result change if your finger were made or heavy metal or wood?

Answer:

When you stick your finger in the water your finger takes the place of some of the water, so the water levels goes, up and the scale tips.

Your finger not only takes the place of some of the water but also stands in for the weight of that displaced water. The weight of the object displacing the water is not a factor. It could be wood, heavy metal or a balloon. You would get the same result.

Today’s Problem:

You have no doubt observed that a cork will always drift over to the side of a water glass and stay there. Can you think of a way to make the cork float in the middle of the glass without touching either the cork or the glass?

Yesterday’s Problem:

You have two glasses, one exactly half full of tea, the other exactly half full of milk. Take a teaspoon of milk from the glass and stir it into the tea. Then take a teaspoon of the tea-milk mixture and stir that into the glass with the milk.

Is there now more milk in the tea than there is tea in the milk? Or, is there more tea in the milk and milk in the tea? [This one is tricky, eh?]

Answer:

As tricky as the problem sounds, there is exactly the same amount of milk in the tea as there is tea in the milk.

Today’s Problem:

Two glasses filled with water are balanced on a scale. What happens to the scale when you stick your finger in one of the glasses? Will that side of the balance tip as it it were heavier?

How would the result change if your finger were made or heavy metal or wood?