Physics Acceleration and Projectile Review Guide Name: Major Concepts 1-D motion on the horizontal 1-D motion on the vertical Relationship between velocity and acceleration https://www.khanacademy.org/science/physics/one-dimensional-motion/acceleration-tutorial/a/acceleratio n-article Difference between constant velocity and constant acceleration http://www.physicsclassroom.com/class/1dkin/lesson-1/acceleration Characteristics of a projectile http://www.physicsclassroom.com/class/vectors/lesson-2/what-is-a-projectile Horizontal motion of an horizontally launched projectile http://www.physicsclassroom.com/class/vectors/lesson-2/horizontal-and-vertical-components-of-velocity Vertical motion of an horizontally launched projectile http://www.physicsclassroom.com/class/vectors/lesson-2/horizontal-and-vertical-components-of-velocity Acceleration of a projectile on the horizontal Acceleration of a projectile on the vertical Relationship between launch angle, height, and range http://www.physicsclassroom.com/mmedia/vectors/mr.cfm Labeled diagram of the trajectory of a launched horizontally projectile Effect of gravity and air resistance on a projectile True or False Correct any false statement 1. Any object has the potential to be a projectile. 2. On lift-off, a rocket is a projectile. 3. The acceleration due to gravity influences both the horizontal and vertical component. 4. The horizontal and vertical components are independent of each other. 5. The greatest range will occur when the launch angle is 45 6. If the horizontal velocity doubles, the time doubles. 7. Hang time is twice the time it takes to reach maximum height. 8. Projectiles launched at complementary angles will have the same range. 9. For an upwardly throw object, the greatest velocity is at the top of the trajectory. 10. For an object launched horizontally, the initial velocity on the y is 0 m/s. 11. An upwardly thrown object may have an initial velocity of 0 m/s. 12. If the velocity vector and the acceleration vector are occurring in the same direction then the object is slowing down. 13. An object in free fall is affected by gravity. 14. The horizontal and vertical components of a projectile are independent of each other. 15. A dropped object and an object launched from the same height will hit the ground at the same time. Problems 1. Find the total displacement of the object using this velocity time graph.
2. A racecar accelerates uniformly from 20.0 m/s to 45 m/s in 7.65 seconds. Determine the acceleration of the car and the distance traveled. 1. A car starts from rest and accelerates uniformly over a time of 26 seconds and travels a distance of 225 m. Determine the acceleration of the car. 2. A student drops a rock from a bridge to the water 12.0 m below. With what speed does the rock strike the water? 3. An astronaut drops a feather from 1.2 m above the surface of the moon. If the acceleration of gravity on the moon is -1.60 m/s2, how long does it take the feather to hit the surface? 4. A bowling ball is thrown horizontally off a 20 meter high cliff with a speed of 20 m/s. a. How far from the base of the cliff does the bowling ball land? b. What was the time of flight? 5. A golf ball travels 200 meters horizontally at a maximum height of 20 meters. Determine the ball s initial horizontal and vertical velocity. 6. A cat is sleeping 40 m from the base of a 150 m high cliff. If a dog rolls a rock off the cliff with a horizontal velocity of 15 m/s will the rock hit the cat? Diagrams 1. Which trajectory has the greatest horizontal velocity? a. V1 b. V2 c. V3 d. they are all equal 2. Which trajectory has the greatest vertical velocity? a. V1 b. V2 c. V3 d. they are all equal 3. A ball is launched horizontally from the top of a cliff with an initial velocity of 20 m/s. The trajectory of the ball is shown below. Express your understanding by filling in the blanks.
4. On the velocity time graph, label each segment with a description of the motion. Explain what happens at 9.0 seconds and how this was represented on the graph. Multiple Choice 1. A bullet is fired at an angle of 45. Neglecting air resistance, what is the direction of acceleration during the flight of the bullet? a. Upward b. downward c. dependent on initial velocity 2. For a projectile, what is its acceleration in the horizontal direction? a. Depends on initial velocity b. Depends on time in the air c. Depends on the velocity on the y-axis d. 0m/s 2 3. Which of the following is an example of projectile motion? a. a bullet being fired from a gun b. a jet lifting off a runway c. a space shuttle orbiting Earth d. dropping an aluminum can into the recycling bin 4. A 10-kg object and a 100-kg object of the same size are dropped from the roof of a building. Which will hit the ground first? (Neglect air resistance) a. they will hit at the same time b. the 10 kg object c. the 100 kg object d. cannot be determined from given information 5. Which of the following statements are true of the time of flight for a projectile? List all that apply. a. The time that a projectile is in the air is dependent upon the horizontal component of the initial velocity. b. The time that a projectile is in the air is dependent upon the vertical component of the initial velocity. c. For a projectile which lands at the same height that it is projected from, the time to rise to the peak is equal to the time to fall from its peak to the original height.
d. Assume that a kicked ball in football is a projectile. If the ball takes 3 seconds to rise to the peak of its trajectory, then it will take 6 seconds to fall from the peak of its trajectory to the ground. Minion Motion 1. A Minion is thrown straight up and reaches his apex (Highest point) 2.4 seconds later. a. Describe the Minion s motion in terms of velocity and acceleration. b. Why is the Minion s initial velocity a non-zero value? c. Calculate the initial velocity of the Minion. d. How high did the Minion go? 2. Next, the Minion fell horizontally out of a 20.3m high window with an initial velocity of 13.5 m/s. a. Describe the Minion s motion in terms of velocity and acceleration. b. How long did it take the Minion to hit the ground? c. How far from the window did the Minion land? d. Sketch a vector diagram of the Minion as he fell out of the window. 3. Explain why the Minion below is not a projectile. Determine which of the graphs below represent the following Minion Motion: a. Falling from a tall building b. bouncing on a trampoline
c. Being tossed into the air and caught at the point of release