Water power and dams
Answers are for parents and teachers.
1
Draw the energy chain of a hydroelectric power station with boxes and arrows. Label each box with the form of energy.
Potential energy (water high up), kinetic energy (falling water), kinetic energy (spinning turbine), electrical energy (generator).
2
With a grown-up, make a pinwheel from paper and a pencil. Blow on it and then hold it under a gentle stream of water from a jug over a sink. Write what you see.
Answers differ. The pinwheel turns when moving air or water pushes it.
3
Write two gains and two costs of building a dam on a river.
Gains: electricity, stored water, fewer floods. Costs: land covered, fish routes blocked, less mud below (any two of each).
4
A dam works 8 hours a day and makes 40 units of electricity each hour. How many units does it make in one day?
8 × 40 = 320 units.
5
Explain to someone at home why the water cycle makes hydroelectric power renewable.
The Sun lifts water as vapour, clouds form and rain refills the river, so there is water to use again.