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Motion Putting It All Together

Page history last edited by Hannah 3 years, 5 months ago
Motion: Putting it All Together

 

 

Experiment Questions:

  1. On a distance vs. time graph, how does an object's motion (speeding up, slowing down, and constant speed) affect the slope of the line?

 

  1. On a speed vs. time graph, how does an object's motion (speeding up, slowing down, and constant speed) affect the slope of the line?

 

Materials:

  • Pasco low friction car

  • 2 rubber bands

  • Computer stopwatch

  • Tape

  • Tape Measure

  • Ruler

 

Jobs: 4 people

  1. Person Launching the car

  2. 2 timers

  3. Stopper – stops the car at the end

 

Procedures:

    1. Use the rubber band and chair to make a launcher.

 

 

 

 

 

 

 

 

  1. Place the launcher behind the starting line (black tape) so that the rubber band is exactly 9 cm from the front of the tape (front = closest side to the rubber band)

     

     

 

 

 

 

 

  1. Place the car so that the back of the car is up against the launcher

 

 

 

 

 

 

  1. From the front of the black tape, take the measuring tape and extend it 3 meters
  2. Place a piece of tape at the 0.75 meter, 1.5 meter, 2.25 meter, and 3 meter mark.

  3. Using the online stopwatch on both computers, your group will be timing the car

  4. Now you are ready to do the experiment just like we did as a class.

  5. Pull back the car and rubber band so the front of the car is against the starting line (the front edge of the tape)

  6. The person launching the car should say, “ready, set, go” and lets go while the timers all start the stopwatch.

  7. The timers should press the "split" button as it goes by meters 0.75, 1.5, and 2.25 when the front of the car passes the tape.

  8. Finally, when the car goes by meter 3, the timers should press the "Stop" button to stop the watch.

  9. The stopper stops the car and gives it back to the launcher

  10. Record the times from both stopwatches in the data table

  11. calculate the Average Time of the car

  12. Calculate the Velocity of the car

 

Data Table/Results:

Time at each distance (sec)

Trial 1

Trial 2

Average Time (sec)

Distance (m)

0

0

0

0

0.603

0.505

0.554

0.75

1.707

1.501

1.604

 1.5

2.983

3.252

3.118

 2.25

5.023

5.279

5.151

3

The inside (closer to the rubber-band) edge of the first black tape tape in front of the chair with the rubber-band launcher was the reference point in our experiment.

Calculating Velocity

  • Finding the velocity at each meter: By finding the slope of the line from the Position/Distance vs. Time graph

Slope = Rise ÷ Run

Slope = (y2- y1) ÷ (x2- x1)

  • SHOW ALL WORK IN YOUR SCIENCE NOTEBOOK!

 

Velocity = Rise÷Run

At Meter 0:

 


= 0 m/s

Velocity = Rise÷Run

From 0 - 0.75 meters: 


= 1.354 m/s

Velocity =Rise÷Run

From 0.75 - 1.5 meters:

 

= 0.714 m/s

Velocity = Rise÷Run

From 1.5 - 2.25 meters:

 

= 0.495 m/s

Velocity =Rise÷Run

from 2.25 - 3 meters:

 

= 0.369 m/s

 

Now Calculate the AVERAGE SPEED of the car from 0 m to 3 m.

Average Speed = Total Distance ÷ Total Time

 

m ÷ s

 

= 0.582 m/s

 

 

Velocity vs. Time Data Table

Avg. Time (sec)

Velocity (m/s)
 

0

0
 

0.554

1.354 
 

1.604 

0.714 
 

3.118 

0.495 
 

5.151 

0.369 

 

 

Data Analysis/Discussions

 

 

 

 

Distance Range

Is the car speeding up, slowing down, or moving at a constant speed?

Did the slope increase, decrease, or stay the same

0 to 0.75 m

 Speeding Up Increase

0.75to 1.5 m

 Slowing Down Decrease

1.5 to 2.25 m

 Slowing Down Decrease

2.25 to 3 m

 Slowing Down Decrease

 

 
 

 

 
 

Distance

Range

Is the car Accelerating, decelerating, or not accelerating?

Is the slope Positive, Negative, or Zero slope
 

0 to 0.75 m

 Accelerating Positive
 

0.75 to 1.5 m

 Decelerating
 

Negative
 

1.5 to 2.25 m

 Decelerating

Negative
 

2.25to 3 m

 Decelerating Negative

 

 

Summary

Partner 1 Summary
          In this activity, we made our own experiment to collect data about a decelerating object, then calculated velocity and made two graphs, which we then analyzed for trends. One was a Distance vs. Time graph, and one was a Speed (or Velocity) vs. Time graph. Both of these were analyzed for slope, as mentioned. We found that, in a Distance vs. Time graph, deceleration forces the slope to level off over time, to decrease. However, with no backward forces in play besides friction, the slope will never pass into the negative range, stopping its fall and then continuing at a zero slope. In a Speed vs time graph, on the other hand, the slope is negative from the very point at which the deceleration starts.

 

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