February 26, Algebraic Method (filled).notebook PHYSICS 11 TEACHER'S NOTES LESSON

Transcription

1 PHYSICS 11 TEACHER'S NOTES LESSON 1

2 Adding Two Vectors Algebraically Going the Other Way: Making Component Vectors 2

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5 Adding Vectors Algebraically Section 2.2 Drag and drop the following steps to the table in the order that you would follow to algebraically add two non perpendicular vectors. Determine the components of the given vectors. Add the x components, and add the y components. Add the component sum vectors to determine the resultant vector. Determine the magnitude of the resultant vector. Determine the direction of the resultant vector. State the resultant vector. Check Answer 5

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7 Adding Vectors Algebraically Section 2.2 d 1 Vector = 2.5 m [W 40 S], and vector = 5 m [E 60 N]. Add the vectors algebraically, using the vector arrows to show the steps. d 2 1. Drag and rotate the black arrow to show vectors d 1 and. d 2 2. Drag and rotate the blue arrow to show the vector components. 3. Use the red arrow to show the total displacement. N W E S d Tx =, d Ty =, d T = Check Answer 7

8 River Crossing Problems Section 2.2 River crossing problems involve independent horizontal and vertical motion. Drag the boat across the river to where you think it might land. The current in (b) is about twice as fast as the boat speed, which is around 10 km/h. (a) (b) (c) N Pier Boat Discussion no current with current flows from left to right with unrealistic current flows from left to right and downward Check Answer 8

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11 ANSWERS TEACHER'S NOTES LESSON 11

12 Adding Vectors Algebraically Section 2.2 Drag and drop the following steps to the table in the order that you would follow to algebraically add two non perpendicular vectors. Determine the components of the given vectors. Add the x components, and add the y components. Add the component sum vectors to determine the resultant vector. Determine the magnitude of the resultant vector. Determine the direction of the resultant vector. State the resultant vector. Back 12

13 Adding Vectors Algebraically Section 2.2 Vector d 1 = 2.5 m [W 40 S], and vector d 2 = 5 m [E 60 N]. Add the vectors algebraically, using the vector arrows to show the steps. 1. Drag and rotate the black arrow to show vectors d 1 and. d 2 2. Drag and rotate the blue arrow to show the vector components. 3. Use the red arrow to show the total displacement. N d 2 W E d T 77 d Tx d Ty d 1 S * Quantities are not drawn to scale. * Quantities are not drawn to scale. d Ty d Tx =, 0.6 m [E] =, 2.7 m [N] = 2.8 m [E 77 N] d T Back 13

14 River Crossing Problems Section 2.2 River crossing problems involve independent horizontal and vertical motion. Drag the boat across the river to where you think it might land. The current in (b) is about twice as fast as the boat speed, which is around 10 km/h. (a) (b) (c) N Pier Boat Discussion no current with current flows from left to right with unrealistic current flows from left to right and downward Back 14

15 Answers for Discussion Questions: Slide 8 Sample Answers: The time it takes for the boat to cross the river in scenarios (a) and (b) should be the same, although in scenario (b) the boat will be east of the dot. Why is the time the same? The current is moving parallel to the shore. There is no y component of the current velocity, as there is with the boat s velocity, so the current velocity does not affect the velocity in the y direction, and therefore does not affect the time. The unrealistic current in (c) does affect the velocity. The current is not parallel to the shore, so the velocity would have to be broken into its x and y components. Since the current is in a downward direction, that y component of the velocity is in the opposite direction to the y component of the boat s velocity, so the velocity across the river is reduced and, therefore, the time needed increases. Back 15