2. Motion Along a Straight Line particle ögn 37 average velocity meðalhraði 37 average x -velocity meðalhraði í x -stefnu 37 x-t graph x-t graf 38

Transcription

1 2. Motion Along a Straight Line particle ögn 37 average velocity meðalhraði 37 average x -velocity meðalhraði í x -stefnu 37 x-t graph x-t graf 38 instantaneous velocity stundarhraði 39 derivative afleiða 40 instantaneous x -velocity stundarhraðic 40 speed ferð 40 motion diagram hreyfilínurit 42 average acceleration meðalhröðun 43 average x -acceleration meðalhröðun í x -stefnu 43 instantaneous acceleration stundarhröðun 44 instantaneous x- acceleration stundarhröðun í x -stefnu 45 v x -t graph v x -t graf 45 a x -t graph a x -t graf 47 free fall frjálst fall 53 acceleration due to gravity hröðun vegna þyngdar 54

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3 v x = lim t 0 t x = dx dt

4 a v t x x = lim = t 0 dvx dt

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13 dt a v v t x x x + = = t v x dt x x 0 0 t a v x av x = dt a dv v v t t x x v v x x x x = =

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15 The slope of the curve in the position vs. time graph for a particle s motion gives: 1. the particle s speed 2. the particle s acceleration 3. the particle s average velocity 4. the particle s instantaneous velocity 5. not covered in the reading assignment Hallatala línu sem sýnir stöðu agnar sem fall af tíma segir til um: 1. hraða agnarinnar 2. hröðun agnarinnar 3. meðalhraða agnarinnar 4. stundarhraða agnarinnar 5. ekki minnst á þetta í lesefninu

16 The slope of the curve in the position vs. time graph for a particle s motion gives: 1. the particle s speed 2. the particle s acceleration 3. the particle s average velocity 4. the particle s instantaneous velocity 5. not covered in the reading assignment Hallatala línu sem sýnir stöðu agnar sem fall af tíma segir til um: 1. hraða agnarinnar 2. hröðun agnarinnar 3. meðalhraða agnarinnar 4. stundarhraða agnarinnar 5. ekki minnst á þetta í lesefninu

17 Is it possible for an object s instantaneous velocity and instantaneous acceleration to be of opposite sign at some instant of time? 1. yes 2. no 3. need more information Er það mögulegt að stundarhraði hlutar og stundarhröðun hans séu á einhverjum tímapunkti með gagnstæð formerki? 1. já 2. nei 3. þarf frekari upplýsingar

18 Is it possible for an object s instantaneous velocity and instantaneous acceleration to be of opposite sign at some instant of time? 1. yes 2. no 3. need more information Er það mögulegt að stundarhraði hlutar og stundarhröðun hans séu á einhverjum tímapunkti með gagnstæð formerki? 1. já 2. nei 3. þarf frekari upplýsingar

19 A train car moves along a long straight track. The graph shows the position as a function of time for this train. The graph shows that the train: 1. speeds up all the time. 2. slows down all the time. 3. speeds up part of the time and slows down part of the time. 4. moves at a constant velocity.

20 A train car moves along a long straight track. The graph shows the position as a function of time for this train. The graph shows that the train: 1. speeds up all the time. 2. slows down all the time. 3. speeds up part of the time and slows down part of the time. 4. moves at a constant velocity.

21 1.1 Analyzing Motion Using Diagrams Applet 1, Problems 1 & 2 Predict Motion Equations

22 1.3 Predicting Motion from Equations Question 1 & 2 Predict Motion Equations

23 The graph shows position as a function of time for two trains running on parallel tracks. Which is true: 1. At time t B, both trains have the same velocity. 2. Both trains speed up all the time. 3. Both trains have the same velocity at some time before t B. 4. Somewhere on the graph, both trains have the same acceleration.

24 The graph shows position as a function of time for two trains running on parallel tracks. Which is true: 1. At time t B, both trains have the same velocity. 2. Both trains speed up all the time. 3. Both trains have the same velocity at some time before t B. 4. Somewhere on the graph, both trains have the same acceleration.

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28 A person standing at the edge of a cliff throws one ball straight up and another ball straight down at the same initial speed. Neglecting air resistance, the ball to hit the ground below the cliff with the greater speed is the one initially thrown: 1. upward 2. downward 3. neither they both hit at the same speed

29 A person standing at the edge of a cliff throws one ball straight up and another ball straight down at the same initial speed. Neglecting air resistance, the ball to hit the ground below the cliff with the greater speed is the one initially thrown: 1. upward 2. downward 3. neither they both hit at the same speed

30 A marathon runner runs at a steady 15 km/hr. When the runner is 7.5 km from the finish, a bird begins flying from the runner to the finish at 30 km/hr. When the bird reaches the finish line, it turns around and flies back to the runner, and then turns around again, repeating the back-and-forth trips until the runner reaches the finish line. How many kilometers does the bird travel? km km km km

31 A marathon runner runs at a steady 15 km/hr. When the runner is 7.5 km from the finish, a bird begins flying from the runner to the finish at 30 km/hr. When the bird reaches the finish line, it turns around and flies back to the runner, and then turns around again, repeating the back-and-forth trips until the runner reaches the finish line. How many kilometers does the bird travel? km km km km

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