Playing with Forces

Objective

To investigate various forces and create differences as to how the work.

Base Difficulty

Medium (It requires students to understand intermediate physics concepts.)

Concept

We live in the world where balance among forces play an important role, figuratively and literally. The balance of these forces is what enables us to be on a rollercoaster without falling out. One of the most famous equations, and important legacies of Newton is F=ma. The equation states that mass and acceleration are directly proportional to force.

So what kinds of forces are there in this world?

We can divide forces to two groups: fundamental forces, and non-fundamental forces.

Fundamental Forces:

1. Gravity: Occurs when two masses attract each other. We experience gravity every day. We are held to the earth by gravitational acceleration constant g.
2. Electromagnetic Force: This is the force that attracts different charges together, and makes opposite charge repell each other.
3. Nuclear forces: There are two nuclear forces. One is weak force and another is strong force. While not having such a great names, these serve to keep protons and the nucleus together.

Non-Fundamental Forces

1. Normal Forces: This is the force that keeps us from falling into the earth. It acts perpendicular to the surface where an object lies.
2. Friction: This lets us walk without slipping!
3. Continuum mechanics: This is a fancy world for pressure, either flowing from water or gas.
4. Tension: This is how strings are able to hold on to objects.
5. Elastic force: Some materials don't like to be changed. Good examples of these forces include balloons bursting or an elastic band flying away.
6. Centripetal force: The force that is needed to keep a body's motion in a circular path.
7. Fictitious Force: The name says it all! When sitting in a moving car it seems like the outside tree appears to be moving. This difference frame can give rise to different forces. A few examples are centrifugal force and coriolis force. These are the basis for relativity.

There are so many forces in the world. So how do they relate? How do we balance them?

• Can you build a series of devices that will push buttons and do things for you? (Like that Honda commercial!)
• How can you use these forces to turn them into energy?
• What is the relationship between these forces and work? How can you use them to do work?
• How are these forces stored?
• How can you use these forces to do work? How can you make it the most effective? (Hint: Look at your car engines!)

Things to Consider

1. Some stored energy can be the dangerous. Make sure the forces are controlled and you cannot be harmed. If needed, equip yourself with proper safety equipment. Check our Safety page for more information.