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8. The speed at which a launcher fires tennis balls is constant, but the angle between the launcher and the horizontal can be varied. As the angle is decreased from 45 degrees to 30. degrees, the range of the tennis balls Elapsed Time = 0.92 5 My =90 m/s Launcher Va # 9.0 m's Horizontal a) O increases b) O decreases c) O remains the same d) O can't be determined 12. Projectile A is launched horizontally at a speed of 20. meters per second from the top of a cliff and strikes a level surface below, 3.0 seconds later. Projectile B is launched horizontally from the same location at a speed of 30. meters per second. The time it takes projectile B to reach the level surface is a) 2.0 s b) 03.0 s c) . 10. s d) 04.5 s 13. The diagram below represents the path of an object after it was thrown. What happens to the object's acceleration as it travels from A to B? [Neglect friction. ] a) . It remains the same b) @ It Increases. c) @ It decreases. d) . can't be determined 4)A player kicks a football at an angle of 30.0 above the horizontal. The football has an initial velocity of 20 m/s. WH is the velocity of the ball at the max height? a.0.0 m/s b. 10.0 m/s c. 17.3 m/s d. 20.0 m/s 5) A cannonball is fired at some angle into the air. If the first second, it moves 5.0 m horizontally. Assuming it doesn't hit the ground and air resistance is negligible, how far does the cannonball move in the next second? a.5.0 m b. More than 5.0 m c. Less than 5.0 m d. Not enough information 6) A ball is thrown into the air at some angle. At the very top of the ball's path, its velocity is a. entirely vertical b. entirely horizontal c. both vertical and horizontal d. zero 7) A projectile is launched from the ground with an initial velocity Vo at an angle 0 above the horizontal. How long wil the projectile to reach the maximum height in air? A)(Vo sin0)/g B) (2Vo sine)/g 8/(850) ON) (7 D) (2Vo sin0)/g E) (Vo tan0)/g 8) A projectile is launched from the ground with an initial velocity Vo at an angle 0 above the horizontal. What is the maximum height of the projectile? z/(0:503 -ON) (a z/(0:UIS ZOA) (3 8/(0:UIS =DAZ) (8 8/(0:uIs ON)( E) (Vo' cos20)/g