Over. Okay, so now we're going to be doing Chapter one problems. 65 2 This one is kind of complicated. We're talking about a patient in therapy, and they have a forearm that weighs 24 5 News, but and lit that can lift 112 thie. Only other significant forces on the harm come from the biceps muscle, which acts perpendicular, perpendicular early, 24 on and a force at the elbow. If the bicep spirits of pole of 232 7 magnitude of the bicep forces 232 years of that, when the forum is raised at 43 degrees, okay, above the horizontal, and then we want to find the magnitude direction of the mobile force. So we know that elbow plus bicep is going to equal this resulting. So now lets you do all this to figure out where we're talking about. So char X y plain our resultant force needs to be just straight up. We know that, and this is the bicycle force, and this is at a angle of 43 degrees. Okay, Cool. So we can rearrange this equation here toe right? In terms of you know this is our minus B. Okay, so in components we can write, he acts are exploiters the X, which equals zero minus 2 32 Time's a sign of for these three to get the X component. So it's 158 Newton's and the ex So sue the same with the why here This becomes 130 2.5 because that is the total weight from the forum, plus the wait. So this is the week er that resulted vector magnitude, and we can subtract B y. So this is 132.5 minus 2 32 Times Co signed a 43 so that comes out to be native. 37. Newton's Okay, clear. So now that we have that, we could find the magnitude of the elbow force. This is a square root of 37 squared plus 1 58 square. I could put that on a calculator. He's our elbow, has a magnitude force of 162 Newtons. So let's draw this and our ex wife trying to figure out what direction the elbow is, right? So if it's 158 Newton's not degrees on the wire, about that 158 newbies north her up in the X direction right such this way 1 50 feet in the negative, 37 down here. So the elbow wasn't doing this kind of force. So for wanting to find this angle here, we can take data equals arc Tangent of negative 37 over 1 58 and we see that this becomes 13 degrees south of horizontal, which is also the same as negative 15 degrees. Cool, then we have the magnitude and the direction of our resulted vector our elbow after not a result of awesome.