3.13. Set Up: Take to be downward. The car travels downward during the time it travels 61.0 m horizontally. Solve: Use the vertical motion to find the time in the air: gives Then gives (b) since Reflect: We calculate the final velocity by calculating its x and y components. 3.14. Set Up: Take to be upward, so and At the highest point in the trajectory, When the object reaches the ground, Solve: (a) and (b) The vertical displacement at is (c) Use and The time from when it is thrown to when it returns to its original height is twice the time it takes it to reach its maxi-mum height. (d) 3.15. Set Up: Use coordinates with the origin at the initial position of the ball and upward. and The trajectory of the ball is sketched in Figure 3.15. Figure 3.15 Solve: (a) From Figure 3.15, and (b) At the maximum height so with and gives (c) gives (d) downward at all points of the trajectory. At the maximum height and so horizontal. (e)
This is the end of the preview. Sign up
access the rest of the document.