Thread: free fall

At time t = 0 s, apple 1 is dropped from a bridge onto a roadway beneath the bridge; somewhat later, apple 2 is thrown down from the same height. Figure 2-25 gives the vertical positions y of the apples versus t during the falling, until both apples have hit the roadway. With approximately what speed is apple 2 thrown down?

Originally Posted by BiGpO6790

[IMG]file:///C:/Users/Nick/AppData/Local/Temp/moz-screenshot-3.jpg[/IMG]At time t = 0 s, apple 1 is dropped from a bridge onto a roadway beneath the bridge; somewhat later, apple 2 is thrown down from the same height. Figure 2-25 gives the vertical positions y of the apples versus t during the falling, until both apples have hit the roadway. With approximately what speed is apple 2 thrown down?

Take the origin to be the release point, and positive downwards.

The time it takes the first apple to reach the roadway tells you how high the roadway is. Since for this the distance from the release point is:



and we know that seconds when is the bridge height.

For the second apple we know that the time to hit the road is seconds. The apples distance from the release point is:



where t is the time from release of the second apple.

As we know the height of the bridge we set this to , and the time of fall which we set to we can now solve for the speed with which the apple is thrown down

CB