Unit 1, Lesson 3: Displacement vs. Time Graphs

Example 1: Constant Velocities Find the velocity at 0.5 seconds, 2.0 seconds, 5.0 seconds. d) Find the average velocity. a) velocity = slope = 0 b) velocity = slope = (60-20)/(3-1) = 20 m/s c) v = (20-60)/(6-4.5) = -26.7 m/s d) Average v = (total displacement)/(total time) = 0 20 min

Example 2: Changing Velocity A rocket takes off and the height is recorded as shown. a) Find the average velocity of the rocket. b) Find the velocity at 20 and 40 seconds. h (m) t (s) 15 10 60 20 135 30 240 40 375 50 540 a) Average velocity = (total displacement)/(total time) = 540/60 = 9.0 m/s 5 min b) Find the slope of the tangent at each point…

Displacement vs. Time for a Rocket 5 min At 20s: v = slope of tangent = (120-0)/(30-10) = 6 m/s At 40s: v = (330-150)/(48-33) = 12 m/s Note: These values are approximate!

Brain Break!

Practice: Complete the Velocity Graphing Exercise. 25 min

Unit 1, Lesson 4: Interpreting Graphs

Interpreting Graphs Describe the motion: Object accelerates from rest 5 min Object accelerates from rest then decelerates and stops Object moves backwards or down and accelerates

Sketch a graph of d vs. t for each: 100 m race Bungee jump (2 bounces) Draw a graph to show an object moving forwards at a constant speed, then slowing down and stopping. Your turn! Sketch a graph of d vs. t for each: 100 m race Bungee jump (2 bounces) Parachute jump 20 min

Brain Break!

Try Graphing This! 15 min

Practice: Complete the Velocity Practice worksheet. 15 min