The Stairs That Return

Investigate how a moving staircase keeps its steps level, folds into a flat floor, carries riders and stops. Use a working model to compare tracks, chains, handrails and brakes. Seven investigations for ages 12 and up.

Library

Shape a moving staircase

Lesson 1

A Stair That Refuses to Tilt

An escalator climbs a slope, but the steps you stand on stay flat. What stops each step from tipping with the slope?

Start

Lesson 2

The Gap at the Edge

Escalator steps pull apart into a staircase, then come together into a flat floor. How do they do that without opening large gaps between them?

Start

Lesson 3

A Steady Turn, an Uneven Ride

The wheel turns perfectly steadily, and the chain it pulls still does not.

Start

Carry a crowd

Lesson 4

The Crowd Going Down

The same crowd, the same machine, the opposite direction.

Start

Lesson 5

Your Hand Gets There First

Your hand and your feet set off together and do not arrive together.

Start

Bring it to a stop

Lesson 6

The Button Anyone Can Press

Why can an escalator that stops too suddenly throw its riders forwards, even though the steps have stopped safely?

Start

Lesson 7

Strong Brake, Snapped Chain

A brake strong enough to stop a full escalator meets a chain that has just snapped.

Start

Review and assessment

Lesson 8

Test: The Stairs That Return

Review the course ideas by applying them to new situations, with kind feedback after every answer.

Locked till you take the prior lesson