Help - Accelerating Incline

The applet shows the motion of a block on an incline with or without friction. The incline is either at rest or accelerating horizontally. The motion can be observed either from the Lab or the Ramp (Incline) frame.

The following material does not belong to this applet and will be replaced shortly.

Click on a number to view its explanation.

  1. Basic Control Buttons

    2. There are four basic control buttons. They are, from left to right:

    / Play/Pause. Clicking starts the motion.

    After Play has been clicked, the button will change into the Pause button . Click it if you want to take a 'snapshot' of the motion at a given instant. To resume the motion, click Play once more.

    Step. Lets you step through the motion in equal time steps.

    Replay. Resets the simulation to the starting point with the previously chosen initial values. If you have the ball's paths displayed, Replay will allow you to compare paths traversed under different conditions, e.g., different initial velocities or different amounts of air resistance or different accelerations due to gravity. After clicking Replay, click Play to restart the motion.

    Reset. Resets the applet to its default setting.

    Adjustments in the initial conditions can only be made after first clicking REPLAY or RESET.

  2. Mass Slider

    3. The slider allows adjusting the masses of the two planets between 2500 and 7500, in unspecified units. The masses of the two planets cannot be adjusted independently, but increasing the mass of one planet decreases the mass of the other planet so that the combined mass is always 10,000.

    By clicking in the slider groove to the left or the right of the slider tab, one can change the two masses by increments of 100 at a time.

  3. Force Vectors

    4. The two planets exert gravitational forces on each other. The Force toggle button allows to either display or hide the two force vectors. The vectors are shown in green.

  4. Velocity Vectors

    5. The Velocity toggle button allows to either display or hide the velocity vectors of the two planets. The vectors are shown in magenta.

  5. Momentum Vectors

    6. The Momentum toggle button allows to either display or hide the momentum vectors of the two planets. The vectors are shown in blue.

  6. Data

    7. The Data toggle button either displays or hides the Data box shown below. If you click on the Data box and drag, you can move it anywhere on the screen or even off the screen.

    The following data are displayed in the Data box. All data are in unspecified units. Subscripts "1" and "2" refer to the planet on the left and on the right, respectively. For an explanation of how the forces and PE or E are calculated, please go to ShowMe or Lesson.

  7. Zoom Slider

    8. The size of the image of the two planets and related vectors can be controlled between 25% and 100% by means of the Zoom slider. By clicking in the groove to the left or the right of the slider tab, one can decrease or increase the slider setting by 1% at a time.

  8. Pause Before Collision

    9. When the "Pause Before Collision" radio button is selected, the motion of the two planets will pause just before the moment of collision. Unselecting the button at this point will cause the planets to resume their motion and collide.

  9. Center of Mass

    10. The center of mass of the two-planet system is indicated by a small red circle.