How do your arms feel in the bath, and why?

• Light, because the water pushes up
• Heavy, because the water pushes down
• The same as in the air

What name do we give the upward push of water?

• Downpull
• Upthrust
• Sidepush

Water pushes up on things that sink as well as things that float.

What happens as you lower a floating ball slowly into water?

• Push grows to match weight
• The push shrinks to nothing
• The water gets weaker

A log floats but a coin sinks. Why?

• The log is colder than the coin
• The coin is bigger than the log
• Packing decides float or sink

A clay ball sinks. You reshape the same clay into a wide bowl and it floats. Why?

• The clay became lighter stuff
• The water disappeared
• The bowl pushes aside more water, so the push grows

Dan says the nail sinks because steel is heavy, and the ship floats because ships use light stuff. What is his mistake?

• Both are the same steel; shape and air inside decide
• Steel changes weight in ships
• Nails are hollow

You test an empty sealed bottle and the same bottle filled with sand. Which floats?

• The bottle filled with sand
• The empty sealed bottle, full of air
• Both sink the same way