In this weeks lab, we did an experiment to answer the question What is the relationship between impulse, force, and time during a collision?
Before the lab, we knew that impulse (J) can be defined as a change in momentum (pafter - pbefore).
Our general procedures of the lab started by crashing an empty cart into the force-probe attatched to the ring stand. we then recorded the carts velocity before the collision and then after the collision. These points are shown in the bottom half of the picture below. Then we found the area under the Force vs. Time graph by highlighting the green trianguar shape shown below.
Then we calculated the impulse of the cart and this work is shown in the whiteboard that we did in class below.
We were also asked how the impulse and the area under the Force vs Time graph compare? By comparing the integral (area of the proabola) and the impulse that we calculated, we saw that after considering there may be minor error in our experiment, that the integral and impulse are the SAME! From this information, we went through the following process to derive the equation below.
We also noticed that the impulse on an object in a collision is constant. This means that force and time are inversely proportional. Forces are equal and opposite.
This just sounds like a bunch of useless scientific facts, but it actually really makes sense. In field hockey, one is supposed to "give with the ball" when they receive it. This means that when someone passes to you, you don't just stick out your stick because then the ball will bounce off and will no longer be in your possession. By increasing the time before the ball and stick make contact, the force of both decrease. See this in action in the video below!
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