1. Define a projectile. 2. What determines how long it will take an 12. A kangaroo jumps from the ground level object to reach the ground when released vertically upwards to a height of 3.0 m. with an initial velocity of zero? How long does it take the kangaroo to come back to the ground? 3. The position-time graph of a ball thrown vertically up is a parabola. Describe the 13. A penny is dropped from a cliff of height velocity of the ball 190 m. Determine the time it takes for the (a) on its way up penny to hit the bottom of the cliff. (b) when it reaches its maximum height 14. A coin tossed straight up into the air takes (c) on its way down 2.75 s to go up and down to its initial release 4. A child throws a soft toy ball vertically point 1.30 m above the ground. What is its upward at 8.0 m/s. It takes 3.3 s to reach its maximum height above the ground? maximum height. 15. If a diver starts from rest, determine the (a) How long does it take the ball to return amount of time he takes to reach the water's to the child's hand? What assumption did surface from the 10-m platform. you make? 16. John drops a key from a window which is (b) What is the ball's final velocity? 5.0 m above a point on the ground below. At the same time, Jane starts walking from a Connect Your Understanding distance towards this point on the ground with a speed of 2.75 m/s. When she reaches this point, she catches the key when it is 1.25 m above the ground. How far was Jane from the point when the key was dropped