Velocity-Time Graphs and Linear Motion Practice Tuesday, September 29, 2015

Tuesday, 9/29 Unit 2: Linear Motion On your warm-up respond to the questions below: A receiver runs down the field at .5 m/s. He realizes he is not going to catch the ball at the rate he is running and accelerates at a rate of 1.5 m/s for 3 seconds. Use GUESS to determine the receiver’s final velocity when he catches the ball. Upcoming dates Thursday, 10/1 – Quiz Monday, 10/5 – Review due Wednesday, 10/7 – Unit 2 test Friday, 10/9 – last day to turn in 1NW extra credit Visit my webpage for more important dates

Tuesday, 9/29 Unit 2: Linear Motion On your warm-up respond to the questions below: A receiver runs down the field at .5 m/s. He realizes he is not going to catch the ball at the rate he is running and accelerates at a rate of 1.5 m/s for 3 seconds. Use GUESS to determine the receiver’s final velocity when he catches the ball. G: Vi = .5 m/s E: Vf = Vi + at S: Vf = 5.0 m/s a = 1.5 m/s t = 3 s S: Vf = .5 + (1.5)(3) U: Vf Vf = .5 + 4.5

Velocity-time graph guiding questions Why are velocity time graph lines always straight? What does the line represent? If an object has a positive velocity, what does that mean about the direction of the motion? If an object has a negative velocity, what does that mean about the direction of the motion? How do you know if an object is speeding up or slowing down? If the velocity-time graph line has a zero slope what does that tell us about the velocity and the acceleration? We cannot determine where an object’s ______ is from a v/t graph, only its ______ in position.

Velocity-time graph guiding questions Why are velocity time graph lines always straight? What does the line represent? The lines are straight because the motion is constant. The line represents constant acceleration. If an object has a positive velocity, what does that mean about the direction of the motion? It is moving away from the reference point. If an object has a negative velocity, what does that mean about the direction of the motion? It is moving towards the reference point. How do you know if an object is speeding up or slowing down? If the line is getting closer to zero it is slowing down. If the line is getting further away from zero it is speeding up. If the velocity-time graph line has a zero slope what does that tell us about the velocity and the acceleration? The velocity is constant and the acceleration is zero. We cannot determine where an object’s position is from a v/t graph, only its change in position.

Diagram and graph hunt – 10 minutes Review the diagrams and graphs Identify what type of motion is depicted Write the number and draw the diagram on your ‘diagram and graph’ hunt sheet.

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Practice Problems

Cool Down How can you determine the change in an objects position on a velocity time graph?