A 'moving sidewalk' in an airport terminal moves at 1.0 m/s and is 35.0 m long. If a woman steps on at one end and walks at 1.5 m/s relative to the moving sidewalk, how much time does it take her to reach the opposite end if she walks (a) in the same direction the sidewalk is moving?

Video transcript

Welcome back everybody. We are in an airport and we have a walk later, which is one of those stretches of runway that move on their own. And we are told that the Waka later is 20 m long and it has a velocity relative to the earth of 0.9 m/s. Now we have a boy on the other end who is going to start running in the same direction As the walk later. And he has a velocity relative to the Walker later of 2.9 m/s. And we are tasked with finding how long it takes for him to reach the end of the walk later. Now, I'm gonna use this notion right here. That distance is equal to velocity times time. But we don't know his velocity relative to the Earth. So we're gonna need to find that boys velocity relative to the Earth is going to be equal to the velocity of the boy relative to the walker leader plus the velocity of the WAka later relative to the Earth. Which that makes sense if you're ever walking down one of those things at this speed, the wake a leader is just gonna make you that much faster. So we know these values. So we are going to plug in what we know here to find this velocity. So let's go ahead and do that. The velocity of the boy relative to the Earth is equal to well, boy, relative to the walk later. 2.9 plus walk later relative to the Earth, 0.9. This gives us a velocity of 3.8 m per second. Now, let's go ahead and use this formula up top to be able to find our time. We're told that our distance is equal to our velocity times time. I'm gonna divide both sides by our velocity. This yields the useful equation that our time is equal to our distance over velocity. Once again, we know the terms on the right here. So let's go ahead and plug those in. We are told that our time is equal to the distance of the walk leader. 20 m divided by the boys philosophy, 3.8 m/s. And then when you plug this into your calculator, you get a final answer of 5.3 seconds corresponding to answer choice. A thank you guys so much for watching. Hope this video helped. We will see you all in the next one.