How Things Work Trivia Quiz

Answer: Guides them into an interlocking row

The slider is the small piece that travels along the zipper when you pull its tab. Channels inside it guide the two rows of teeth together. The teeth fit into one another and stay joined after the slider passes. Moving the slider back separates the rows again.

Answer: Loops of thread

The rough strip has tiny hooks, while the softer strip has loops. Pressing the strips together catches many hooks in those loops. Peeling them apart releases the hooks, so the fastening can be used again. Velcro is a brand name; this type of fastening is called hook-and-loop.

Answer: Rolls ink from inside the pen onto the paper

The ball sits in a socket, a small holder at the pen's tip that lets it turn. As it rolls across the paper, its surface picks up ink from inside and carries it outside. That leaves the line you see on the page. The ball fits closely in its socket, helping control how much ink comes out.

Answer: The two arms turn around a pivot

A clothes peg is also called a clothespin. Its two arms work as levers: they turn around a point called a pivot, between the handles and the gripping ends. Squeezing the handles together makes the other ends move apart. When you let go, the spring presses the gripping ends together again.

Answer: It stores energy by winding more tightly

Turning the key winds the spring more tightly, storing energy supplied by your hand. As the spring unwinds, it turns gears: wheels with teeth that pass movement from one part to another. These move the toy's wheels or other moving parts. The toy stops when the spring can no longer supply enough energy to keep it moving.

Answer: The chain carries movement between toothed wheels

The pedals turn a toothed wheel beside them. Its teeth fit into the gaps in the chain, pulling the chain around another toothed wheel at the back. That movement turns the rear wheel and helps drive the bicycle forward. An axle is a shaft at the centre of a rotating part, such as a wheel.

Answer: It stops much of the dome's vibration

The dome is the bell's rounded metal cover. When struck, it makes tiny, rapid back-and-forth movements called vibrations, which create sound waves in the air. Holding it firmly reduces those movements, so the ringing dies away. The movement can be too small to see even while you hear the bell.

Answer: They control the direction in which the soap flows

A valve acts like a little gate that opens or closes a passage. In this pump, valves keep soap moving in the intended direction rather than flowing backwards. Pressing the head pushes soap out of a small chamber, or space inside the pump, through the nozzle where it comes out. Letting go allows the chamber to fill again from the bottle.

Answer: The lever gives the cutters more force for the same hand effort

The handle works as a lever: a bar that turns around a fixed point called a pivot. Your hand moves through a larger distance than the cutters do, allowing them to press harder on the paper. Their sharp edges cut out small discs. A tray underneath many desk punches collects those pieces.

Answer: The teeth of a metal comb

The cylinder is a turning drum with small pins sticking out of it. These pins bend and release the teeth of a metal comb, making them vibrate to produce musical notes. This is what 'pluck' means here, rather like pulling and releasing a guitar string. The positions of the pins determine which notes play and when, allowing the tune to repeat.