--- title: Car safety: brakes, seat belts and airbags — a lesson of Mova's school · trees and pragmatics description: «Car safety: brakes, seat belts and airbags», a lesson of the technology course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: A moving car is heavy and fast, and it cannot simply stop: the brakes have to turn all that movement into heat, which takes --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Technology](https://md.mova.elamur.ai/free/en/corpora/school/technology/) / Car safety: brakes, seat belts and air… # Car safety: brakes, seat belts and airbags Lesson 18 of the technology course of Mova's primary school: 18 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/technology/18-car-safety/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/0/) — A moving car is heavy and fast, and it cannot simply stop: the brakes have to turn all that movement into heat, which takes time and road. - [1](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/1/) — If a car does stop suddenly in a crash, everything inside that is not held keeps going forward at the same speed, including people, which is why seat belts matter on every single trip. - [2](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/2/) — Modern cars are built to protect the people inside: the belt holds you, the airbag cushions the head, and the front of the car crumples on purpose to slow everyone more gently. - [3](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/3/) — Picture the school run: you climb into your booster seat, click the belt across your chest and hips, and later hop out on the pavement side, away from the traffic and the cyclists. - [4](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/4/) — Outside a car the rules matter just as much: drivers cannot see everything, so you never play behind parked cars and you keep clear of anything reversing. - [5](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/5/) — Pressing the brake pedal pushes fluid along pipes that squeeze pads onto discs on the wheels, and the rubbing turns the car's movement into heat. - [6](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/6/) — A car cannot stop instantly; even at 30 miles an hour it needs several car-lengths, and more on a wet road. - [7](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/7/) — ABS anti-lock brakes notice when a wheel stops turning and skids, and release and press the brakes many times a second so the driver can still steer. - [8](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/8/) — A seat belt locks if the car suddenly slows or the belt is pulled fast, and it is worn on every trip in every seat, across the chest and hips, not the neck or tummy. - [9](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/9/) — The three-point seat belt was invented at Volvo in 1959, and the company let other carmakers use it for free. - [10](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/10/) — In a crash, sensors set off a small charge that fills a nylon airbag with gas in less time than a blink, bursting out with great force, and then it quickly empties. - [11](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/11/) — Children sit in the back, and a rear-facing baby seat never goes in front of an active airbag. - [13](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/13/) — Babies ride facing backwards because their necks are weak. - [14](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/14/) — Child locks are small switches on the edge of the back doors that stop them opening from inside, and passengers get out on the pavement side and check for bikes; opening a door into a cyclist is called dooring. - [15](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/15/) — Drivers have blind spots behind and to the sides, and a small child can be hidden behind a car; lorries have huge blind spots, and if you cannot see the driver's mirrors, the driver cannot see you. - [16](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/16/) — Parking sensors send out sound pulses and time the echo, beeping faster as the car gets closer to something, a bit like a bat, but they do not see everything. - [17](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/17/) — Speed cameras measure speed with radar or by timing a car between two points; a person hit at 20 mph is much less likely to be killed than at 30 mph, which is why there are 20 mph zones near schools. - [18](https://md.mova.elamur.ai/free/en/corpora/school/technology/18-car-safety/18/) — The front and back of a car are crumple zones, built to squash in a crash and take up energy so the people inside are slowed more gently. - ← previous: [Inside a car: engine, gears and the dashboard](https://md.mova.elamur.ai/free/en/corpora/school/technology/17-inside-a-car/) - next →: [Electric cars and charging](https://md.mova.elamur.ai/free/en/corpora/school/technology/19-electric-cars-and-charging/) - ↑ back to [Technology](https://md.mova.elamur.ai/free/en/corpora/school/technology/)