1. Preliminary Questions 2B.1.1: Position, Velocity, Acceleration Plots The plot to the right represents the motion of an object. During period 1, the object’s velocity is increasing, constant, or decreasing? Determine the velocity of the object at 20.0 s. During period 1, the object’s acceleration is positive, zero, or negative? Increasing, constant, or decreasing? Determine the acceleration of the object between 0.0 s and 15.0 s. Determine the distance traveled by the object during the first 10.0 s.

2. Prelim Q KEY 2B.1.1: Position, Velocity, Acceleration Plots 1.During period 1, the object’s velocity is increasing, constant, or decreasing? First, note that the plot is of velocity [vertical] vs. time [horizontal] Velocity starts the period at 0 m/s and increases uniformly to 15.0 m/s. 2.Determine the velocity of the object at 20.0 s. 15.0 m/s. - Go to 20.0 s on the horizontal axis. - Move straight up [vertically] until you reach the plot [green, point B]. - Move straight left [horizontally] until you reach the vertical axis [velocity]. - Read the value.

3. Prelim Q KEY 2B.1.1: Position, Velocity, Acceleration Plots 3.During period 1, the object’s acceleration is positive, zero, or negative? Increasing, constant, or decreasing? Acceleration = slope of v vs. t plot. Slope between 0.0 s and 15.0 s is positive and does not change. 4.Determine the acceleration of the object between 0.0 s and 15.0 s.

4. Prelim Q KEY 2B.1.1: Position, Velocity, Acceleration Plots 5.Determine the distance traveled by the object during the first 10.0 s. Distance from a v vs. t plot: Area under the curve. Area of a triangle = ½ (base) (height) = ½ (10.0s) (10.0 m/s) = 50 m OR: Distance = (avg. velocity) (time interval)

5. Follow up questions.2B.1.1: Position, Velocity, Acceleration Plots The plot to the right represents the motion of an object. During period 2, the object’s velocity is positive, zero, or negative? Increasing, constant, or decreasing? During period 2, the object’s acceleration is positive, zero, or negative? Increasing, constant, or decreasing? Determine the acceleration of the object during period 2. Determine the distance traveled by the object during period 2. Determine the velocity of the object at 10.0 s.

6. KEY. Follow up.2B.1.1: Position, Velocity, Acceleration Plots The plot to the right represents the motion of an object. During period 2, the object’s velocity is positive, zero, or negative? Increasing, constant, or decreasing? During period 2, the object’s acceleration is positive, zero, or negative? Increasing, constant, or decreasing? Determine the acceleration of the object during period 2. Slope = zero. Determine the distance traveled by the object during period 2. (15 m/s)(5 s)=75 m Determine the velocity of the object at 10.0 s. 10.0 m/s.

7. Follow up questions, 2.2B.1.1: Position, Velocity, Acceleration Plots The plot to the right represents the motion of an object. During period 3, the object’s velocity is positive, zero, or negative? Increasing, constant, or decreasing? Determine the velocity of the object at 25.0 s. During period 3, the object’s acceleration is positive, zero, or negative? Increasing, constant, or decreasing? Determine the acceleration of the object during period 3. Determine the distance traveled by the object during period 3.

8. KEY. Follow up 2.2B.1.1: Position, Velocity, Acceleration Plots The plot to the right represents the motion of an object. During period 3, the object’s velocity is positive, zero, or negative? Increasing, constant, or decreasing? Determine the velocity of the object at 25.0 s. 5.0 m/s. During period 3, the object’s acceleration is positive, zero, or negative? Increasing, constant, or decreasing? Slope of a line is constant. Slope is negative. Determine the acceleration of the object during period 3. (15m/s – 5m/s)/(25s – 20s) =10/5=2m/s/s Determine the distance traveled by the object during period 3. ((15m/s + 5m/s) / 2) (25s – 20s) = 50m