Kinematic Curves Worksheet • Split the problems between the groups • Draw the position, velocity, and acceleration vs. time graphs on whiteboards • Check your answers with other groups • Whiteboard: • Table 1 and Table 2 GP1 • page 1: 4, 5 • Table 1 and Table 2 GP 2 • page 1: 7, 10 • Table 3 and Table 4 GP 1 • page 2: 3, 4 • Table 3 and Table 4 GP 2 • page 2: 6, 8 Ch. 3 Vectors • • • • • • Vectors and Scalars Unit Vectors Column Vectors Magnitude, Direction Cartesian and Polar Coordinates Calculations: components, resultants • Trigonometry! • Lots of practice problems Vectors and Scalars • scalar quantity – completely specified by a single value with an appropriate unit and has no direction. – Use an italic letter: A • vector quantity – completely described by a number and appropriate units plus a direction. – Use an arrow: A General Physics C1 3 Important Concepts Column Vector • How can we describe position using a using column vector? typical vector notation column vector notation General Physics C1 5 Using Vectors Magnitude and Direction • A vector may also be represented by its magnitude and direction. • Magnitude • The magnitude of the vector has physical units • The magnitude of a vector is always a positive number General Physics C1 7 Direction • Based on forming a right triangle from r and θ H • x = r cos θ • y = r sin θ O • SOH-CAH-TOA A General Physics C1 8 Cartesian to Polar Coordinates • r is the hypotenuse and θ an angle • θ must be counterclockwise from positive x axis for these equations to be valid General Physics C1 9 Example problem • Jane leaves her house and walks 5.0 blocks east and then proceeds north until she is 7.8 blocks from home at an angle of 50 degrees North of east. How many blocks north did she travel? General Physics C1 10 Using Vectors Using Vectors Problems from the Student Workbook • p. 3-1: 1, 2, 5, 6 • p. 3-2: 8, 10, 11, 13, 14 • p. 3-3: all problems • p. 3-4: 26, 27, 28 • Whiteboard your results • Use column vectors whenever possible Practice - Problem 3.37 Mary needs to row her boat across a 120 m wide river that is flowing to the east at a speed of 1.0 m/s . Mary can row the boat with a speed of 2.0 m/s relative to the water. a) If Mary rows straight north, how far downstream will she land? b) Draw a picture showing Mary s displacement due to rowing, her displacement due to the river s motion, and her net displacement. • Whiteboard!!! Practice - Problem 3.41 A flock of ducks is trying to migrate south for the winter, but they keep being blown off course by a wind blowing from the west at 6.0 . A wise elder duck finally realizes that the solution is to fly at an angle to the wind. If the ducks can fly at 9.0 relative to the air, what direction should they head in order to move directly south? • Whiteboard!!!
© Copyright 2024