Density, measuring it, and evaporation
Answers are for parents and teachers.
1
Find the density of an object with mass 135 g and volume 50 cm³ and name the material from the table.
135 : 50 = 2.7 g/cm³ – aluminium.
2
Calculate the volume of a bar of soap 2 cm thick, 5 cm wide and 10 cm long.
100
3
Test five waterproof, unbreakable objects from home in a bowl of water and record which float.
Results depend on your objects: wood, plastic lid, cork float; a coin, key, stone sink.
4
Why do drops form on a window or cold glass in the evening? Explain with condensation.
Water vapour in the air touches the cold surface, cools and turns into droplets.
5
Why does washed laundry dry faster in summer than in winter?
Evaporation speeds up at higher temperature.