User talk:Twomble

Seatbelts save Lives

You know how in high speed car crashes the windshield is either cracked or broken? That is from someone who wasn't wearing there seat belt, its simple physics. When a car is stopped abruptly then whoever is inside of it is going to keep on moving until they are stopped, thats what a seat belt is for. Many deaths could have been and could be prevented all from the use of a seat belt. After you read this paper you will know the physics of car crashes and how necessary it is to wear a seat belt. Newton's first law states that "An object that is at rest will remain at rest or an object that is moving will continue to move in a straight line with constant speed, if and only if the net force acting on the object is zero." Because of this in the case of a car accident without a seat belt you are going to go flying because you are an object at motion and you will continue to go at constant speed until outside force strong enough acts upon you.

When you are riding in a car the car has momentum. You have the same amount of momentum as the car does. But when the car comes to an abrupt stop i.e. a car wreck such as colliding with a brick wall, the car will lose all its momentum but you will keep going until a force acts on you like the brick wall acted on the car. A seat belt is that force, without it you are going to go through the windshield into the brick wall.

Momentum can be calculated as P = M x V. An SUV that weighs 2200 kg or 1000 lbs going at a constant rate of 70 mph or 31.3 meters per second then what would you momentum be? Simple you just multiply the mass or the weight in kilograms by the velocity or the rate at which its moving in meters per second like this:   P = 2200 x 31.3 P = 68,860 kilogram meters per second Lets take a look at how much force it will take to stop a child who isnt wearing a seat belt once you've had an accident. Your driving 70 mph on a highway and you crash into another car going the opposite direction. A child in the front seat isn't wearing his or her seatbelt and the child weighs 44 lbs. The forces on the child have to add up to zero for it to stop moving therefore the force needed to stop it will have to be equal to the impulse which in equation from is F = m x a, its momentum can be calculated like this: P = 20 x 31.3 P = 626 kgm/s Say that the car collides with a brick wall and stops in 0.22 seconds, the force needed to stop the child can be calculated using the impulse formula: F = m x a                                                  F = 626 kgm/s / .22 s                                                   F =  2845.45 Newtons of force Some people think that they can hold their arm out to stop the child in the event of a crash but it takes 981 N just to bench press 225 lbs which the average person will probably not be able to do. It is not possible to hold out your arm and stop a child the forces are too strong. This also applies to people who think that it is safer to hold a baby instead of putting it in a car seat. If you were to have a wreck your momentum would send you crashing into a part of the car crushing the baby. You don't have the strength necessary to stop yourself in a car wreck, that's what seatbelts and airbags are for.