A car traveling at a speed of 18m/s (approximately 40 MPH) crashes into a solid concrete wall. The driver has a mass of 90 kg.
a) what is the change in momentum of the driver as he comes to a stop?
b) what impulse is required in order to produce this change in momentum?
c) how does the application and magnitude of this force differ in two cases: the first, in which the driver is wearing a seatbelt and the second in which he is not wearing a seat belt and is stopped instead by contact with the windshield and steering column? will the time of action of the stopping force change? explain..
I would really much appreciate it. points to any answers given :)What is the change in momentum of the driver as he comes to a stop?
a) change in momentum = change in speed x mass
b) Impulse is a force acting over a period of time that equals the change in momentum. You haven't specified a time interval in which the driver is brought to a halt so this can't be worked out.
See this web page for more details and worked examples
http://www.physics247.com/physics-homewo
c) The seat belt gives which means the time taken to stop the driver is longer. Hence the force is smaller (remember F x t = Impulse) than if the driver hits the interior of the car, as that won't give as much as the seat belt.What is the change in momentum of the driver as he comes to a stop?
a)
Momemtum = mass * velocity.
At 18 m/s what is his momentum? What is it a 0 m/s? That is your change in momentum
b)
I = impulse, F = force, p = momentum, t = time, d = %26quot;delta%26quot; or %26quot;change in...%26quot;
I = 鈭?(F)dt, and F = dp/dt
I = 鈭?(dp/dt)*dt
I = 鈭?dp
I = change in momentum
Impulse required to cause that change in momentum is equal to that change in momentum.
c)
Yes (I think). It should take more time for him to travel forward into the windshield/steering wheel then it will take for the seatbelt to reach its maximum stretching distance.
