Rube Goldberg Physics

This post is looking to clarify some information from our last post, and discuss some more of the physics behind our machine.

Firstly, forces do not transfer from one object to another. Force= Mass x Acceleration. Therefore force is directly dependent on an objects mass and acceleration. if the acceleration increases the force increases.

Or dominoes are a good example for most of the physics we need to understand, and are as close to ideal as most objects come. While dominoes are stationary the the forces acting on each domino is equal.

Dominoes have inertia, so they obey Newton's fist law of motion. (an object at rest or in motion will remain as such unless acted upon by an outside force.) Inertia is an objects resistance to being moved. The smaller the mass of an object the less inertia it has. Since the dominoes have minimal mass there inertia is small, therefore, they can easily be forced into motion.

In the case of our first set of dominoes our ruler/candle hammer knocks the first domino and causes it to accelerate from its stationary position. When this domino accelerates it transfers its momentum to the next domino; this process continues through the series of dominoes.

Dominoes also can help explain Newton's second law of motion which states that Force= Mass x Acceleration.  The greater the mass of an object the more it resists acceleration, yet the more force an object has the more it is accelerating. Our dominoes have a small force because they have a small mass, since the mass is small and the force acting on the first domino is small the acceleration is not as great.

Dominoes are also a good example of Newtons third law. For every action there is an equal and opposite reaction. Dominoes exhibit this when they fall over. When one domino falls over it knocks another one over. The domino can knock another domino over because they have the same mass; therefore the reaction is equal. The action in this case is a domino falling: for every action (the domino falling) there is an equal (The next domino falling) and opposite reaction (is the force that is being pushed back on the fallen domino).

Speed is the distance over time. How fast an object moves over a span of time. Our Rube Goldberg  machine over its entirety has speed as do each separate step. The easiest way to see this is in our first step. When the car travels down the ramp. The speed is how much distance (the length of the ramp) is covered over time (how long it takes the car to reach the bottom of the ramp).  The car in this section also exhibits acceleration. Our car can also be used to describe velocity. velocity is a speed in a given direction. Since our car is traveling forward in a set direction it exhibits a forward velocity. The given average velocity of our car would be measured by taking into account the speed of the entire trip and averaging it. This mans average velocity takes into account many instantaneous velocities (which are an objects velocity at any given time).

Acceleration is what occurs when an objects velocity changes. in the case of our car the velocity is going from being less to more from the top of the ramp; this means the car is accelerating.

Momentum is an objects mass times its velocity. Momentum and acceleration are related in that they acceleration is dependent on an objects momentum.

Potential energy is equal to mass x gravity x height of an object. Potential energy is highest at higher points. For example the point with the highest potential energy in our machine is the ramp that the car accelerates down. At the top of the ramp the car has the highest potential energy, and the bottom of the ramp this energy is converted into kinetic energy. Kinetic energy is 1/2 mass time velocity squared.