How does Newton's second law of motion apply to car safety?

I need to make a powerpoint presentation for this, thankyou for any help :)|||force applied = rate of change of momentum.


So to reduce the force in a crash - the rate of change of meomentum needs to be reduced - i.e. the decelration - so an air bag slows the passenger down gradually or crumple zones on the front/back of the car will gradually bring it to a halt rather than a sudden stop.|||State Newtons' 2nd Law


Explain how it gives rise to F=ma.


In a crash, m is your mass, a is your acceleration (deceleration if you prefer) and F is the force which makes you decelerate.


Explain that if F is large (e.g. if F is the force of the windscreen on you during a sudden impact), this causes the injuries


Explain that you therefore have to reduce F to reduce the injuries


F = ma, m is fixed so we must reduce a; how to reduce a?


Answer: extend the time over which deceleration occurs (since a = (v-u)/t ), where v -final velocity = 0 and u = initial velocity)


Seat belts extend the time by maintaining contact with your body and stretching slightly while you are being decelerated; so F is the smaller force of the belt on you (instead of the larger force of the screen on you).


The KEY POINT is to increase the deceleration (i.e impact) time This reduces your 'rate of change of momentum' (which you mentioned when stating Newton's 2nd Law, didn't you).





You could give a worked example with figures to calculate F.





Good luck