A small rock is thrown vertically upward with a speed of 22.0 m/s...

Question

A small rock is thrown vertically upward with a speed of 22.0 m/s from the edge of the roof of a 30.0-m-tall building. The rock doesn't hit the building on its way back down and lands on the street below. Ignore air resistance. (b) How much time elapses from when the rock is thrown until it hits the street?

Accepted Answer

Hello rubio. So in this problem a ball is thrown vertically upward with a speed of 10 m per second from the top of a building of 50 m. Air resistance is negligible. And how much time does the ball leaves? So we have delta H. Since it's going down negative 50. The ball is thrown with an initial initial velocity FBI 10 m/s. Also parabolic path which has been ground find the time it takes. And we know in free fall that the acceleration is just the acceleration of gravity. So we have the values given to the problem and we didn't start this problem by recalling the economic regions. B. F. B. I plus 80. The X. Was the I. T. Was one happy T spread you have squared with the I squared was too you know, we're given some distance, some initial velocity and G. You want to find T. Now we can see an equation to that we have to t terms. So this using this equation as possible, what we need watch that, it's pretty difficult. And for equation one we see that we have T. But we need a V. F. We can get a V. F. From equation three. So this is the route that we're going to take. So from equation three, see the VF is equal to plus or minus square root with the I squared plus two. A. In this case, agent. Now you can see that I did plus four miles in this case when the ball reaches the ground, the F. Is going to be less than zero. So we should take the negative, so V F is going to be the negative square root, the I squared. That's two G wh equation one that the F B. I plus G times T. M. So we have two equations for VF. We want to find T. So we can set them people to each other in the south negative V I squared Plus two G Delta H equal to the other. The F B I G T. Now we can rearrange this equation. Get an equation for T. T. Is equal to negative square root of B I square to age minus me. I over we can see from the diagram that we do that we have the eye, we have delta age, we have G. So we can now make these substantive insolvency. T is equal to negative square roots 10 m/s squared two times negative second squared negative 50 m, Remind us that term by 10 m per cent. All this is divided by 9, 20 meters per second this calculation and you get that T is for 37 seconds. Answer choice. This is great

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