Presentation on theme: "Reading Assignment: (3.1)"— Presentation transcript:
1 Reading Assignment: (3.1) What is this vector indicating?A velocity with a 1.5 cm componentA displacement with a 1.5 cm componentA displacement vector with the components (3.0 cm, 4.5 cm)A position vector to a place at (3.0 cm. 4.5 cm)
2 Short exerciseDraw the picture for the following problem, label, and write an appropriate vector equation:In a dance, you are standing in a spot, and your partner is located 5 steps to the right of you. He takes 5 steps back, 10 steps to his left. Which displacement does he need to undergo to end up beside you?
3 Short exerciseDraw the picture for the following problem, label, and write an appropriate vector equation:You are observing deer. First, you spot the buck 200m at NNE. A few seconds later, he surfaces again north of you. From the time that has passed you determine that the buck can not have further than 80 m away from the first position. What is the buck’s new position vector?
4 Refinement for average velocity Displacement vectorPosition vectorTime t2Position vectorTime t1observerdefines reference pointAverage velocity:change in position over timePosition vectors:bound to a reference point
5 You watch a ground hog poke his head out of a hole 20m due North of your position. About 15 s later, he appears at a distance of 45 m West of you.Determine its displacement.Determine its average velocity.
6 Instantaneous velocity Direction of average velocity?Strategy: bring the two points closer together.
12 Reading Assignment: (3.2) Which of the particles below has zero acceleration?A baseball is flying beyond the playing field for a home run.A child in a Ferris Wheel being spun around at constant speed.A glider is sliding off an inclined air track.A car is slowing down on an icy straight road.
13 A ship’s echo on a radar screen is moving according toin which all lengths are in km and times in hours.Find the position at time zero, after 30 min and after 1 hour.Find the velocity as a function of time; then calculate it at time zero, 30 min and 1h.Find the acceleration as a function of time; then calculate the acceleration at zero. 30 min and 1 h.Draw positions into an x-y coordinate system, and indicate the respective velocity and acceleration vectors.
14 ExampleA toy train is traveling around a circular track. Its position changes with time asFind the position of the train after 5 s.Find the velocity of the train after 5 s.yx