Impulse Momentum: Comparing Forces

[marisa29]

1. 2) A car is moving at 60.0 m/s and crashes into a wall. The messenger is not wearing his seat belt.
a. What is the average force acting on the passenger of 70 kg if he is brought to rest by a collision with the windshield and dashboard that lasts 3.5 ms.
b. Compare this value of the average force with the average force exerted by an air bag that bring the passenger to rest in 40 ms.



2. delta(p)=Force*delta time
Fave= delta p/ delta t

The Attempt at a Solution

a) Momentum of the person
70 kg * 60 m/s = 4200 kg*m/s
F ave= 4200/.0035 sec= 1.2*10^ 6 N

B) 4200/.040 sec= 10.5*10^4 N

 

[Poop-Loops]

So what is your question? You need to start being more specific what you need help with.

Your math looks fine and I would think that's the right answer if your equation are correct.

 

[Moetasim]

In response to the content provided, I would like to explain the concept of impulse and momentum and how it relates to the scenario given. Impulse is defined as the change in momentum of an object and is equal to the force applied multiplied by the change in time. In this case, the change in time is the duration of the collision between the car and the wall, which is 3.5 ms. Momentum, on the other hand, is the product of an object's mass and velocity.

In the given scenario, the car is moving at a constant velocity of 60.0 m/s and crashes into a wall. The passenger, who weighs 70 kg, is not wearing a seat belt and is brought to rest by the collision with the windshield and dashboard. The average force acting on the passenger is calculated by dividing the change in momentum by the change in time.

a) The first step is to calculate the momentum of the passenger before the collision. This can be done by multiplying the mass of the passenger by the velocity of the car, which gives a value of 4200 kg*m/s. Then, dividing this value by the duration of the collision, which is 3.5 ms, gives an average force of 1.2*10^6 N acting on the passenger.

b) In comparison, if the passenger was wearing an airbag, the duration of the collision would be longer, approximately 40 ms. Using the same formula, the average force exerted by the airbag would be 10.5*10^4 N. This value is significantly lower than the force exerted without an airbag, which shows the importance of wearing a seat belt and having safety features such as airbags in a car.

In conclusion, the concept of impulse and momentum helps us understand the forces acting on an object during a collision. It also highlights the importance of safety features in vehicles to reduce the impact force and protect passengers. As scientists, it is important to continue studying and improving these safety measures to make our daily lives safer.