FIGURE EX11.6 is an incomplete momentum bar chart for a collision that lasts 10 ms. What are the magnitude and direction of the average collision force exerted on the object?

Video transcript

Hey everyone. So this problem is dealing with conservation of momentum. Let's see what it's asking us. The graph shown below describes the collision of a body consider the duration of the collision as 21 milli and the value of the average collision force experienced by the body. So our multiple choice answers here are a negative 714 newtons B negative 142 newtons C 714 newtons or D 142 newtons. So the first thing we're going to do here is look at this graph. So we can see our initial momentum is positive and then we have this force J X and then our final momentum is negative. And so the momentum of this collision force J X is what we're solving from our conservation of momentum equation. We can recall that our initial momentum is equal to our final momentum. And so in this case, our total initial momentum is gonna be everything that happens prior to this this final moment. So that means that we'll have P I X plus J X is equal to P FX. And we're solving for shave X So we can just rearrange this equation. So it will be P FX minus P I X from the graph, we can determine that P FX is negative six can see that there. So that's a negative six kg meters per second minus P initial which is nine so nine kg meters per second. So J X equals negative kilogram meters per second. From here, you can recall that momentum is given by P equals force multiplied by time we're solving for the force of this momentum for J X. And the time was given to us. And the problem as milliseconds or 21 times 10 to the negative three seconds. So our force is equal to our momentum. Uh negative 15 kg meters divided by second and divided by our time or 21 times 10 to the negative three seconds. We plug that into our calculator and we get negative 714 newtons. And that aligns with answer choice. A so A is the correct answer to this problem. That's all we have for this one. We'll see you in the next video.