The following assignment requires that you access the following website:

http://www3.interscience.wiley.com:8100/legacy/college/halliday/0471320005/simulations6e/index.htm

 

Equations: 

Ball 1 - Constant velocity equation:                

Ball 2 - Constant acceleration equation:          

 

Instructions:

Click on the Constant velocity versus acceleration simulation on the left hand scroll bar to access this simulation.  Listen to the Audio Intro before beginning the simulation. 

 

Two balls are shown on your screen. Both will move to the right when you start the simulation. The upper ball moves with a constant velocity. The lower ball starts from rest, but moves with constant acceleration. You can set the lower ball's acceleration using the slider in the bottom right corner. The simulation stops when one ball reaches the right side of the screen. You must Reset the simulation before it will allow you to begin another.  You must also manually Clear the Trace of the graphs if you do not wish to use the graphs anymore.  Graphs of position and velocity vs. time are shown for each ball.

Begin the simulation with the default value of acceleration (1m/s2).

 

Questions:

1.         What is the velocity of the ball that moves with constant velocity?

            5m/s

 

 

2.            How do you know this from the graph of its position versus time graph?  How do you know this from its velocity versus time graph?

i)

            ii) the horizontal line of the velocity vs. time graph has a value of 5m/s

 

 

3.            How far does the accelerating ball travel by the end of the race?

It appears to be 8m from the graph. To verify, , so, when               a = 1.0 m/s2 and t = 4s, d = 8m

 

4.            Calculate the average speed of the accelerating ball.  Show your calculation.

=

Now change the acceleration to 2.0 m/s2 and rerun the simulation.

 

5.            Calculate the new average speed of the accelerating ball.  Show your calculation.

 

 

 

6.            At what time do the two balls have the same velocity during the race?  Which graph gives you this information?

It appears to be at about 2.5 s from the intersection of the two lines on the velocity vs. time graph.   To check:

 

 

7.            Experiment with the acceleration until you find a value that ends the race in a tie.  Write this value.  Show the calculation that demonstrates why this value works.

a = 2.5m/s2

for the constant velocity ball: 

            for the constant acceleration ball: 

 

8.            Determine this average speed of the accelerating ball.  Show your calculation.

 

 

9.            How does this value compare to the speed of the constant velocity ball?

 

They are the same value because they cover the same distance in the same period of time.

 

 

10.         Describe the position versus time graphs of the two balls in words.

 

Constant Velocity – a slanted line with positive slope

            Constant acceleration – an upward curving parabola

 

11.         Describe the velocity versus time graphs of the two balls in words.

 

Constant Velocity – a horizontal line

Constant acceleration – a slanted line with positive slope