Mass in Motion
Detailed App Info:
Application Description
Mass in Motion illustrates the conservation of momentum and the transformation of kinetic energy in elastic and inelastic 1D collisions.
First, on the bottom panel you can setup the collision by moving the sliders for the mass (in kilograms), the initial velocity (in meters per second, positive velocity is motion to the right) and elasticity (0 - completely inelastic collision, 1 - completely elastic collision). Click on the marbles themselves to choose which marble's parameters you wish to modify. Marbles may move while you alter the parameters but don't let that worry you! They are just positioning themselves such that when they collide it will be in plain sight. As you alter the mass the marbles will become larger and smaller to reflect that.
Once you are satisfied with the parameters you have chosen, hit the green Engage button and watch the marbles tumble towards each other and finally collide with a sound (that you can disable if you want)! You can hit the Reset button to get them to move back to their starting positions. Depending on the parameters you chose the marbles might bounce off each other, or get stuck together! Can you find parameters where before the collision both marbles are moving, but after the collision only one is moving? How about a set of parameters where only one marble is moving before AND after the collision (hint: it doesn't have to be the same marble!)?
In the top panel you can examine the data from before the collision (Initial row) and after collision (Final row). Data before the collision will be known as soon as you alter the parameters, while data after the collision will only display after the marbles have collided. Using the buttons on the left you can select whether you want to examine velocity, momentum or kinetic energy. For each quantity the data is separated into three columns. The first two relate to the red and blue marbles, while the last column shows the value of that quantity for the entire system. Can you relate these values to the motion of the marbles? Is the total momentum conserved when the elasticity is changed? What about the total kinetic energy? Can the system have no total momentum but still have total kinetic energy?
First, on the bottom panel you can setup the collision by moving the sliders for the mass (in kilograms), the initial velocity (in meters per second, positive velocity is motion to the right) and elasticity (0 - completely inelastic collision, 1 - completely elastic collision). Click on the marbles themselves to choose which marble's parameters you wish to modify. Marbles may move while you alter the parameters but don't let that worry you! They are just positioning themselves such that when they collide it will be in plain sight. As you alter the mass the marbles will become larger and smaller to reflect that.
Once you are satisfied with the parameters you have chosen, hit the green Engage button and watch the marbles tumble towards each other and finally collide with a sound (that you can disable if you want)! You can hit the Reset button to get them to move back to their starting positions. Depending on the parameters you chose the marbles might bounce off each other, or get stuck together! Can you find parameters where before the collision both marbles are moving, but after the collision only one is moving? How about a set of parameters where only one marble is moving before AND after the collision (hint: it doesn't have to be the same marble!)?
In the top panel you can examine the data from before the collision (Initial row) and after collision (Final row). Data before the collision will be known as soon as you alter the parameters, while data after the collision will only display after the marbles have collided. Using the buttons on the left you can select whether you want to examine velocity, momentum or kinetic energy. For each quantity the data is separated into three columns. The first two relate to the red and blue marbles, while the last column shows the value of that quantity for the entire system. Can you relate these values to the motion of the marbles? Is the total momentum conserved when the elasticity is changed? What about the total kinetic energy? Can the system have no total momentum but still have total kinetic energy?
Requirements
Your mobile device must have at least 2.06 MB of space to download and install Mass in Motion app. Mass in Motion was updated to a new version. Purchase this version for $0.99
If you have any problems with installation or in-app purchase, found bugs, questions, comments about this application, you can visit the official website of Pavel Sountsov at http://sites.google.com/site/appsforphysics/mass-in-motion.
Copyright © 2012 Pavel Sountsov
