# What will be needed in order to restore the balance if necessary?

You have a beam balance, the kind of scales that tips from one side to the other, depending on the weight on each side. On the left side lies a kilogram of ice. On the right side lies the standard kilogram. The pans are in balance.
After a while all the ice melted.
Does the balance tip to the right, to the left, or does it remain unchanged?
What will be needed in order to restore the balance if necessary?

# A yacht drops anchor

A yacht drops its anchor overboard. What happens to the water
level?

# A ball fell into a vessel

A wooden ball fell into a high cylindrical vessel. The diameter of the vessel and the diameter of the ball is 5 cm and 4 cm respectively. Can you get the ball without touching the vessel?

# What is the density of the material from which the object is made?

In the vessel are two immiscible liquids with densities ρ1 and ρ2 and layers of thickness h1 and h2 respectively. From the surface of liquid is lowered a streamlined object which reaches the bottom right at the moment when its speed becomes zero. What is the density of the material from which the object is made?

# A lake on the moon with a boat on it…

Since gravity is much weaker on the moon, everything weigh only 1/6 of its Earth-weight. Imagine there is a lake on the moon with a boat on it…
This boat has a draft of 1 meter in terrestrial freshwater lakes.
How deep will sit the boat in the water of the moon lake?

# Iron-nails & Iron weights. Do they keep the balance?

You have a balance beam, the kind of scales that tips from one side to the other, depending on the weight on each side. 10 kg of the iron-nails balanced on the scales by iron weights. The balance beam submerged in water. Are the scales in balance?

# On the bottom of …

A ball of radius r = 3 cm rested on the bottom of a vertical, cylindrical vessel which has radius R = 9 cm. The density of the ball is in two times less than the density of water. What volume of water should be poured into the vessel so that the ball has ceased to exert pressure on the bottom of the vessel