For the exercises in this chapter, use the approximate value of remember that the velocity is equal to zero at the highest g = 10 m/s2 for the acceleration due to gravity. point.) E1. A steel ball is dropped from a diving platform (with an initial E10. Suppose that the gravitational acceleration on a certain velocity of zero). Using the approximate value of g = 10 m/s2: planet is only 4.0 m/s2. A space explorer standing on this a. What is the velocity of the ball 0.7 seconds after its release? planet throws a ball straight upward with an initial velocity b. What is its velocity 1.4 seconds after its release? of 17 m/s. E2. For the ball in exercise E1: a. What is the velocity of the ball 3 seconds after it is thrown? a. Through what distance does the ball fall in the first b. How much time elapses before the ball reaches the high 0.7 seconds of its flight? (Assume g = 10 m/s2.) point in its flight? b. How far does it fall in the first 1.4 seconds of its flight? Ell. A bullet is fired horizontally with an initial velocity of E3. A large rock is dropped from the top of a high cliff. Assum- 800 m/s at a target located 200 m from the rifle. ing that air resistance can be ignored and that the accelera- a. How much time is required for the bullet to reach the tion has the constant value of 10 m/s2, how fast would the target? rock be traveling 6 seconds after it is dropped? What is this b. Using the approximate value of g = 10 m/s2, how far does speed in MPH? (See conversion factors.) the bullet fall in this time? E4. Suppose Galileo's pulse rate was 75 beats per minute. E12. A ball rolls off a shelf with a horizontal velocity of 3 m/s. a. How many beats per second is this? At what horizontal distance from the shelf does the ball b. What is the time in seconds between consecutive pulse land if it takes 0.45 s to reach the floor? beats? E13. A ball rolls off a table with a horizontal velocity of 3 m/s. If c. How far (in meters) does an object fall in this time when it takes 0.45 seconds for the ball to reach the floor, how dropped from rest? high above the floor is the tabletop? (Use g = 10 m/s2.) d. What is this distance in feet (use the conversion factors on the inside front cover)? E14. A ball rolls off a table with a horizontal velocity of 3 m/s. If it takes 0.4 seconds for it to reach the floor: E5. A ball is thrown downward with an initial velocity of a. What is the vertical component of the ball's velocity just 14 m/s. Using the approximate value of g = 10 m/s2, what is before it hits the floor? (Use g = 10 m/s2.) the velocity of the ball 3.0 seconds after it is released? b. What is the horizontal component of the ball's velocity E6. A ball is dropped from a high building. Using the approx- just before it hits the floor? imate value of g = 10 m/s', find the change in velocity E15. A ball rolls off a platform that is 3 meters above the ground. between the first and sixth seconds of its flight. The ball's horizontal velocity as it leaves the platform is 5 m/s. E7. A ball is thrown upward with an initial velocity of 13 m/s. a. How much time does it take for the ball to hit the ground? Using the approximate value of g = 10 m/s2, what are the (See example box 3.3, use g = 10 m/s2.) magnitude and direction of the ball's velocity: b. How far from the base of the platform does the ball hit the a. 1 second after it is thrown? ground? b. 2 seconds after it is thrown? E16. A projectile is fired at an angle such that the vertical com- E8. How high above the ground is the ball in exercise 7: ponent of its velocity and the horizontal component of its a. 1 second after it is thrown? velocity are both equal to 50 m/s. b. 2 seconds after it is thrown? a. Using the approximate value of g = 10 m/s2, how long does it take for the ball to reach its high point? E9. At what time does the ball in exercise 7 reach the high point b. What horizontal distance does the ball travel in this time? in its flight? (Use the approximate value of g = 10 m/s2, and