Machines & Inventions questions for kids

Questions about wheels, wires, tools and clever inventions.

Why do planes fly?
Why do lights turn on?
Why do cars have wheels?
Why do trains run on tracks?
Why do phones need charging?
Why do fridges keep food cold?
Why do washing machines spin?
Why do robots have sensors?
Why do cars have brakes?
Why do lifts go up and down?
Why do bicycles stay balanced?
Why do keys open locks?
Why do cameras take pictures?
How do escalators move?
Why do wheels roll?
What is a lever?
How do cranes lift heavy things?
Why do seatbelts keep us safe?
How do remote controls work?
What are gears?
Why do machines need batteries?
How do clocks keep time?
Why do bikes have chains?
What is a pulley?
How do planes slow down after landing?
Why do cars need engines?
What is a circuit?
How do microphones hear sound?
Why do doors have hinges?
How do printers print pictures?
What is a motor?
Why do computers have screens?
How does a keyboard work?
What is the internet?
Why do bridges need strong shapes?
How do traffic cameras work?
What is a sensor?
Why do helmets protect heads?
How do submarines go underwater?
What is an engine?
Why do tools make work easier?
Why do traffic lights use red, yellow and green?
Why do vacuum cleaners suck up dust?
Why do touchscreens know where your finger is?
Why do huge ships float even though they are heavy?
Why do car airbags puff up so fast?
Why do screws have twisty lines?
Why do toasters pop bread up?
Why can helicopters stay still in the air?
Why does Wi-Fi work without wires?
Why do so many machines have buttons?
Why do drones stay balanced in the air?
Why do cranes not fall over?
Why do elevators have emergency phones?
Why do electric trains need overhead wires?
Why do tunnels sometimes have emergency doors?
Why do roller coasters need big first hills?
Why do bicycles use gears?
Why do wind turbines face the wind?
Why do submarines sink without filling with water?
Why do robots need cameras?
Why do barcode scanners use red light?
Why do escalator steps stay level?
Why do cranes use long arms?
How do revolving doors keep spinning?
How do lifts know which floor to stop at?
How do automatic doors know someone is there?
How do submarines rise back to the surface?
How do skyscrapers stay standing in strong wind?
How do spacecraft use gravity to change speed?
How do airbags inflate so quickly?
Why do bridges use triangles?
How do 3D printers build objects layer by layer?
Why do roller coasters not fall off the track?
How do electric motors spin?
Why do inventions often begin with a problem?
How do machines extend what humans can do?
Why do fridge doors seal with magnets?
How does a bicycle bell make a ringing sound?
Why do keyboards have little bumps on F and J?
How does a sewing machine stitch so fast?
Why do laptops have fans inside?
How does a vending machine know a coin is real?
Why do escalator steps disappear at the ends?
How does a guitar tuner hear the right note?
Why do scissors cut better near the hinge?
How does a dishwasher spray water everywhere?
Why do headphones have left and right sides?
How does a bike pump push air into tyres?
Why do oven doors have thick glass?
How does a fridge light turn off?
Why do printers need different colour inks?
How does an electric toothbrush vibrate so fast?
Why do clocks sometimes tick?
How does a rice cooker know rice is done?
How does a zipper hold two sides together?
Why are aeroplane windows rounded instead of square?
Why are train wheels slightly cone-shaped?
How can an anchor stop a giant ship?
Why does an escalator handrail move at the same speed as the steps?
How does a toilet cistern stop filling when it is full?
Why do washing machine doors lock during a wash?
How does a microwave know its door is closed?
Why do car tyres have grooves?
How do windscreen wipers stay pressed against curved glass?
Why are many pencils hexagonal instead of round?
How does a stapler bend the metal underneath the paper?
How does a retractable pen click in and out?
Why does a tape measure snap back into its case?
How does a kettle switch itself off?
Why can't you open a pressure cooker while it is pressurised?
How does a smoke detector notice smoke before you do?
Why do seatbelts suddenly lock when you pull them fast?
How does a ratchet turn one way but lock the other way?
Why do screws need different-shaped screwdrivers?
How does a drill chuck grip different-sized drill bits?
How do cable cars grip a moving cable without falling?
How do railway points move a train onto a different track?
How does a thermostat know when to stop heating?
How do car windows stop closing when something is trapped?
How does a parking sensor know a wall is close?
Why do revolving sprinklers turn without a motor?
How does a spray bottle turn liquid into a fine mist?
Why does a shopping trolley have wheels that swivel?
How does a paper shredder pull paper in by itself?
How do aircraft black boxes survive violent crashes?
How do railway tracks steer a train onto a different line?
How can a heat pump move warmth from cold air into a house?
Why can an induction cooktop heat a pan without a glowing element?
Why doesn't every fire sprinkler go off when one detects heat?
Why does metal rust?

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