PHYS 1401 – General Physics I

Linear Motion Computer Activity

 

Lab Partner: ___________________             Lab Partner: __________________________

Set-up

Boot the computer and start Safari (this activity doesn’t seem to work with IE explorer on the Mac).  Go to the web address phet.colorado.edu.  Click on the Play with Sims button.  On the page that appears click on the Motion link, then click on the moving Man icon.  Finally click on the Run Now button.

 

Part I – Constant Position

Enter 2.5 in the position box, and then click Run.

 

Q1)  Describe what the man does when you click run.

 

 

Q2)  Sketch the graphs of position vs. time, velocity vs. time, and acceleration vs. time in the space below.

 

 

 

 

Click on the Clear button and then click Yes on the box that asks you to confirm.

 

Now enter -2.5 in the position box, the click Run.

 

Q3)  How does the result differ when you enter -2.5 m, than when you enter 2.5 m?  Be specific.

 

 

 

Q4)  Was +2.5 m to the right or left of the origin?

 

 

Q5)  Was -2.5 m to the right or left of the origin?

 

 

Q6)  What does the sign of the position tell you?

 

 

Part II – Constant Velocity

Click on Clear and then Yes in the confirm box.  Enter 1.0 in the velocity box, and then click Run.  Click on Stop once the man runs into the wall.

 

Q7)  Describe what the man does when you click run.

 

 

Q8)  Sketch the graphs of position vs. time, velocity vs. time, and acceleration vs. time in the space below.

 

 

 

 

Q9)  How is the graph of position vs. time different in this case than from the first two runs?

 

 

 

Click on the Clear button and then click Yes on the box that asks you to confirm.

 

Now enter -1.0 in the velocity box, the click Run.  Click on Stop when the man runs out of room.

 

Q10)  How does the result differ when you enter -1.0 m/s, than when you enter 1.0 m/s?  Be specific.

 

 

 

Q11)  When the man moved at +1.0 m/s, did he move to the right or left of the origin?

 

 

Q12)  When the man moved at -1.0 m/s, did he move to the right or left of the origin?

 

 

 

Q13)  What does the sign of the velocity tell you?

 

 

Part III – Constant Acceleration

Click on Clear and then Yes in the confirm box.  Enter 1.0 in the acceleration box, and then click Run.  Click on Stop once the man runs into the wall.

 

Q14)  Describe what the man does when you click run.

 

 

Q15)  Sketch the graphs of position vs. time, velocity vs. time, and acceleration vs. time in the space below.

 

 

 

 

Q16)  How is the graph of position vs. time different in this case than from the previous runs?

 

 

 

Click on the Clear button and then click Yes on the box that asks you to confirm.

 

Now enter -1.0 in the acceleration box, the click Run.  Click on Stop when the man runs out of room.

 

Q17)  How does the result differ when you enter -1.0 m/s/s, than when you enter 1.0 m/s/s?  Be specific.

 

 

 

Q18)  When the man accelerated at +1.0 m/s/s, how did the velocity graph change over time?

 

 

Q19)  When the man accelerated at -1.0 m/s/s, how did the velocity graph change over time?

 

 

Q20)  What does the sign of the acceleration tell you about the velocity?

 

 

Part IV – Constant Acceleration with non-zero initial velocity

Click on Clear and then Yes in the confirm box.  Enter 1.0 in the acceleration box and 2.0 in the velocity box, and then click Run.  Click on Stop once the man runs into the wall.

 

Q21)  Describe what the man does when you click run.

 

 

Q22)  Sketch the graphs of position vs. time, velocity vs. time, and acceleration vs. time in the space below.

 

 

 

 

Q23)  In this case, when the man accelerated at +1.0 m/s/s how did the velocity graph change over time?

 

 

Click on Clear and then Yes in the confirm box.  Enter -1.0 in the acceleration box and 2.0 in the velocity box, and then click Run.  Click on Stop once the man runs into the wall.

 

Q24)  Describe what the man does when you click run.

 

 

Q25)  Sketch the graphs of position vs. time, velocity vs. time, and acceleration vs. time in the space below.

 

 

 

 

Q26)  In this case, when the man accelerated at -1.0 m/s/s how did the velocity graph change over time?

 

Click on Clear and then Yes in the confirm box.  Enter -1.0 in the acceleration box and -2.0 in the velocity box, and then click Run.  Click on Stop once the man runs into the wall.

 

Q27)  Describe what the man does when you click run.

 

 

Q28)  Sketch the graphs of position vs. time, velocity vs. time, and acceleration vs. time in the space below.

 

 

 

 

Q29)  In this case, when the man accelerated at -1.0 m/s/s how did the velocity graph change over time?

 

 

Click on Clear and then Yes in the confirm box.  Enter 1.0 in the acceleration box and -2.0 in the velocity box, and then click Run.  Click on Stop once the man runs into the wall.

 

Q30)  Describe what the man does when you click run.

 

 

Q31)  Sketch the graphs of position vs. time, velocity vs. time, and acceleration vs. time in the space below.

 

 

 

 

Q32)  In this case, when the man accelerated at 1.0 m/s/s how did the velocity graph change over time?

 

 

You should have observed that the acceleration tells you the slope of the velocity.  When the acceleration is positive the slope of the velocity is positive and when the acceleration is negative, the slope of the velocity is negative.

 

Q33)  When the velocity and acceleration were both positive did the man speed up or slow down?

 

 

Q34)  When the velocity and acceleration were both negative did the man speed up or slow down?

 

Q35)  When the velocity was negative and the acceleration was positive did the man speed up or slow down?

 

Q36)  When the velocity was positive and the acceleration were both negative did the man speed up or slow down?

 

 

Q37)  Summarize how the directions of velocity and acceleration compare when the man speeds up.

 

 

Q38)  Summarize how the directions of velocity and acceleration compare when the man slows down.