A walkway for the Sinai agama
The Sinai agama is a lizard that lives on rocky ground in the deserts of Sinai and the Eastern Desert. Its body and behaviour fit its home. Its colour matches rock, its legs and toes help it run and grip, and it eats insects. Like many desert lizards, it warms its body in the morning sun and then hides in the shade or in a crack in the rocks when the ground is very hot. Now imagine a school in the desert. A dark paved walkway gets too hot at noon for the lizards to cross, and children might step on them. This is a problem to solve with engineering. First write the needs. Lizards need shade, a cooler path, hiding places and safety from feet. People need a safe, flat walkway that costs little and uses simple materials. Criteria and constraints guide the design. Look at wild lizards from a distance. Never catch or touch them.
| Lizards need… | People need… |
|---|---|
| shade at noon | a safe, flat walkway |
| a cooler path | a low cost |
| hiding places | simple materials |
| safety from feet | room for wheelchairs and bags |
Problem and needs. In a notebook write the walkway problem in one sentence. Make a two-column list of what lizards need and what people need. Then write three criteria (what the design must do) and two constraints (money, time, materials). Share your list with a partner. Do you agree on the most important need?