HomeHomeHomeHome
                                 


1D Motion Simulation Page
(there are 3 simulations on this page)


BackButton
________________________________________




Constant Velocity vs. Constant Acceleration Simulation
(c) Andrew Duffy, Boston University, Dept. of Physics

In the simulation below, you can race two cars against each other.  The red car moves with constant velocity (no acceleration), while the blue car accelerates from rest with a constant acceleration.  The results are shown as a "dot plot" motion diagram for each car, as well as a plot of position-vs-time or velocity-vs-time for each car.

FullPageSimulation
(c) Andrew Duffy, Boston University, Dept. of Physics

Suggested Exercises and Observations:
 
1) Adjust the starting position of the red car with the first slider beneath the graphs.
  • Start with the red car even with the blue car at position 0.


2) Maximize the constant velocity of the red car to 10 m/s with the second slider.

3) Maximize the constant acceleration of the blue car to 2 m/s/s with the third slider.

4) Start the race by pushing the (reset) and (play) buttons.

  • The lower graph is a "dot plot" or "motion diagram" of each car.
  • Each car "drops" a dot at its location at regular intervals (1 second apart)


5) Use the bottom buttons to switch between graphing the car positions or velocities.

6) Notice that :

  • the slope of the position-vs-time graph is the instantaneous velocity of the car.
  • the slope of the position-vs-time graph for the red car is constant.
  • the slope of the position-vs-time graph for the blue car can change with time.
  • the slope of the velocity-vs-time graph is the instantaneous acceleration of the car.
  • the slope of the velocity-vs-time graph for the red car is zero (it does not accelerate).
  • the slope of the velocity-vs-time graph for the blue car is constant (constant acceleration).
  • the dots in the motion diagram of the red car are evenly spaced.
  • the dots in the motion diagram of the blue car are spaced increasing far apart.

________________________________________
TopButton





  Dot Plot Motion Diagrams Simulation
(c) Andrew Duffy, Boston University, Dept. of Physics

In the simulation below, you can race two cars against each other.  Here, you can adjust the starting position, the starting velocity, and the acceleration of each car.  You can also set the acceleration of the cars to be negative.  The results are shown as a "dot plot" motion diagram for each car.  The simulation will end as soon as either car "leaves" the plot region (either to the left or to the right). 
FullPageSimulation
(c) Andrew Duffy, Boston University, Dept. of Physics

Suggested Exercises and Observations:
 
1) Play with different starting positions, velocities, and accelerations.
  • If you give a car a negative acceleration, you must give it a positive starting position, or the simulation will end immediately.

2) Start the race by pushing the (reset) and (play) buttons.

  • The lower graph is a "dot plot" or "motion diagram" of each car.
  • Each car "drops" a dot at its location at regular intervals (1 second apart)

3) Notice that a "negative acceleration" is not always the same as a "deceleration"

  • if the car has positive velocity (is currently moving to the right), then a negative acceleration causes the car to slow down (decelerate).
  • but if the car is at rest or has a negative velocity (is currently moving to the left), then a negative acceleration causes the car to speed up (to the left).

4) Be aware that :

  • a "positive acceleration" indicates the velocity is getting more positive or less negative.
  • a "negative acceleration" indicates that the velocity is getting less positive or more negative.
  • "decelerating" describes an object slowing down (regardless of direction)
  • "accelerating" describes an object speeding up (regardless of direction)


5) Note that the spacing of the dots is an indication of the magnitude of the car's velocity

6) Note that an increasing spacing between dots indicates the car is accelerating (increasing the magnitude of its velocity).

________________________________________
TopButton





Freefall Simulation
(c) Andrew Duffy, Boston University, Dept. of Physics

In the virtual demo below, a ball falls under the influence of gravity (it experiences an acceration of -9.8 m/s/s.  The vertical "dot plot" motion diagram on the left shows the increasing dot spacing indicative of an accelerating object.  On the right, the position, velocity, and acceleration of the ball are all plotted as function of time. 
FullPageSimulation
(c) Andrew Duffy, Boston University, Dept. of Physics

Suggested Exercises and Observations:
 
1) Click on the (Launch up to 20 m/s) button to switch from having the ball "Dropped from Rest" from a height of 20 meters above the ground, to having the ball shot upwards with from the ground with an initial velocity of 20 m/s.

2) Notice that in both cases, the acceleration is constant over time at -9.8 m/s.  The negative sign indicates the the positive y-axis is directed upwards, but gravity is directed downwards.

3) Note that the velocity changes over time with a constant negative slope.  The slope of the velocity-vs-time plot is equal to the (constant) acceleration due to gravity: -9.8 m/s/s.

4) Note that the position-vs-time plot has a parabolic profile.
________________________________________
TopButton
External Links to Original & Similar Simulations
(warning : these links will take you outside the UCSD webpage)
TopButton
BackButton 

last updated : 08/22/18