Grade 5 · Unit 4: The way we see things

Seeing behind you

Use mirrors to see round corners and over walls.

Motorbike mirrors show the rider what is behind.

Looking behind

Drivers and riders use mirrors to see behind them without turning round. Light from the cars behind reflects off the mirror into the driver’s eyes. This is a rear-view mirror.

Motorcycle mirrors are slightly curved outwards so that the rider sees more of the road behind.

Periscopes

A periscope is a tube with two mirrors at each end, set at an angle. Light enters at the top, reflects off the first mirror down the tube, then off the second mirror into your eye. Submarines use periscopes to see above the water.

Periscopes were used in submarines and in trenches, so people could look out without being seen.

Mirrors at bends

On narrow hill roads and in car parks there are big round mirrors at bends. They are convex mirrors – they curve outwards. They show a wide view, so drivers can see cars coming round the corner.

Convex mirrors make things look smaller and further away, so drivers must still drive slowly at bends.

At the dentist

A dentist uses a small mirror on a handle to see the backs of your teeth. Hairdressers hold a mirror behind you so you can see the back of your head.

A dentist’s mirror is warmed or coated so that your warm breath does not mist it up.

What I learnt