Respuesta :
Answer:
it is equal to negative 5/24 feet per second, and it's negative because the ladder, the top of the ladder, is moving down the wall, so we have a negative rate.
Step-by-step explanation:
In this problem. We have a ladder that's leaning against the wall of a building. KR ladder is 13 feet long. Okay, I'm going to go ahead and label that l for ladder. You see, we form a right triangle here. I'm gonna label the horizontal acts and the vertical. Why? We are told that the bottom of the ladder is moving away from the building at a rate off 0.5 feet per second. So that's DX DT. Secret will 0.5 feet per second. What we're trying to find is how quickly the top of the ladder is moving down the wall when the base of the ladder is five feet from the wall. Okay, so the point where X is five feet, we want to know how quickly the latter is moving down the wall. So we have a Pythagorean theorem here. X squared plus y squared is equal to elsewhere. I want to go ahead and substitute in 13 for L. Because that is constant. It's not going to change so we can go ahead and put in 13. I want to take the derivative of both sides with respect to t. I'm gonna have to X dx DT plus two. Why d y d t and that's going to be equal to will. The derivative of a constant is just zero. Now I'm gonna substitute in what? We know. I have a two here. I know. Access five. I knew. Know that DX DT is 0.5. I do not know why at this point, OK, But I know I'm trying to solve for d y t t. So I'm gonna go have put that in there. So off to the side. I have to figure out what? Why is well using my migrant there? I'm here. I know access five I'm solving for why? And I know l is 13. So why squared is going to be equal to 13 squared minus five squared, which is 144. Why is equal to 12 so I can go ahead and put 12 in here going to calculate this out? This is gonna be five plus 24 d Y d t is equal to zero. 24 d Y d t is going to be equal to negative five, so it is equal to negative 5/24 feet per second, and it's negative because the ladder, the top of the ladder, is moving down the wall, so we have a negative rate.
