Project Data Analysis
The purpose of this lab was to find out that things that slow down the momentum in a collision ultimately reduce the force exerted on the object. We attempted to model the concept of crumple zones in cars by placing absorbent foam on the front of a collision cart. The force sensor at the end of the track would record the force exerted as the cart collided with it. We hypothesized that if absorbent foam were used, the impulse force on the cart would be reduced greatly. In the real world, this would result in a crash being slowed down to the point were the sudden change in momentum would not greatly disturb the human body. As a control, we collided a cart (of masses, 500g, 750g, 1000g) to determine what a car collision with no crumple zones would be like. For each run, we also had the speed of the cart remain the same. From here went started testing the foam crumple zone.
From the data collected during our runs with the foam crumple zone, we found that no matter what the weight of the car was (speed remaining constant) the impact force was reduced to some extent. The greater the masses of the cart, the less effect the crumple zone had upon the level of the force. With this in mind we determined that the amount of foam crumple zone used would allow us to determine the amount of force absorbed. If in our control run (cart mass 500g) the average force exerted on the sensor was 38.662N and in the 2cm foam run the average force exerted is 10.14N, then the force absorbed by the foam is 28.522N. This force reduction allows one to determine (in the real world) what the best amount of foam would be to get the best controlled deceleration for a car of a certain weight at a certain speed.
Errors in our data seem negligible in scale and were hardly avoidable. The speed of the cart was slightly varied from run to run, but this was canceled out for the most part by the amount of runs we did and the averages from the data that we took. The sensitivity and finicky nature of the program and equipment we used also may have affected out data. Finally human error must be taken into consideration. The way the foam was attached, the speed we let the car go at each time, and other such mistakes must be recognized. All of these things considered, though, barley affect what we feel is very good data, representative of what we were looking for.
Future study of crumple zones at this level would concern the identification of good materials to use as crumple zones. Easily achieved, this data would allow someone to find what materials absorb the best at high or low speeds and with large or small masses behind it.
