P10.7 Safety first Flashcards
How can safety helmets keep you safe?
The helmet is designed to increase the impact time. With a longer impact time the rate of change of momentum per second is reduced
How can seat belt keep people safe?
Time taken to stop someone in a car is longer if they are wearing a seat belt
Seat belt acts across the chest, so it spreads the force out
How do air bags keep people safe?
Spread the force of an impact across the upper part of a person’s body. It also icnreases the impact time
How can cushioned surfaces reduce the risk of danger?
The duration of the impact is longer than it would be if the surface had been hard like concrete. So the person’s momentum is reduced to zero over a longer time by the cushioning effect. Change of momentum per second is therefore reduced.
