Force Problem with crash test car

AI Thread Summary
To calculate the average force acting on a dummy during a crash test, one must first understand the concepts of impulse and momentum. The scenario involves a car moving at 11.4 meters/sec colliding with a wall, causing a 59kg dummy to move 0.66 meters before stopping. It is essential to define the system, focusing on either the dummy or the car, and to analyze the forces involved during the collision. Using conservation of momentum and the impulse-momentum relationship will aid in determining the average force. A systematic approach, starting with known variables and desired outcomes, is recommended for solving the problem effectively.
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A set of crash tests consists of running a test car moving at a speed of 11.4 meters/sec (26 mph) into a solid wall. Strapped securely in an advanced seat belt system, a 59kg (130 lbs) dummy is found to move a distance of 0.66 meters from the moment the car touches the wall to the time the car is stopped. Calculate the size of the average force which acts on the dummy during that time.

Where do I start?

And how do I calculate average force?
 
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You start by reading up a bit on impulse of a force.
 
You are going to need to define your system first. Are you looking at the forces on the Dummy or Car. Then you have to conceptualize why is going on, which system is accellerating, and when is this occurring. Then use conservation of momentum and the relationship with impulse momentum. From there you should be able to find the force acting on the dummy.

This is how I would approach the problem.
 
well i always start out by listing what i know about the situation, and then list what i want to know. That way i have a clear mind of what I am looking for, do that first and then attempt to solve it
 
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