Download Physical Science Review

Physical Science Review
Non-Contact Forces- Fields
Field- a force between two objects that are not touching
Three types of fields- gravitational, electric, magnetic
Gravitational field is affected by distance and mass. More distance less force. More mass more force.
 Electric field is affected by distance. The farther away the charge, the less force.
 In electric field, the opposite charges attract. Like charges repel
 Magnetic field is affected by distance. The farther away a magnet, the less force.
 In magnetic field, the opposite poles attract. Like poles repel.
 On a magnet, the poles have the strongest field. I know this because the magnetic field lines are closer together.
Electromagnets use an electric field to make some objects magnetic. The more coils the stronger the electromagnet.
Potential Energy
*There are three types of potential energy: elastic, gravitational, and chemical
*Gravitational potential energy is affected by height and mass. More mass more GPE. The higher the object
the more GPE. Example- the top of the first hill on a rollercoaster has the most GPE. The formula: GPE= M x H
*Elastic Potential energy is affected by stretching or compressing. The more stretched or compressed, the more
EPE.
*Chemical potential energy comes from the bonds breaking in a molecule. Anytime there is a chemical
change there is CPE. The fuel on a rocket has CPE. It is burned to make the rocket move.
Force Diagrams
 Forces have magnitude (strength) and direction.
 Balanced forces have a net force of zero.
balanced force.
We use vectors to show this.
Objects at rest & constant speed are a
 Unbalanced forces accelerate. They are speeding up, slowing down, or changing
directions. The net force of an unbalanced force is NOT zero.
 Net force- forces in the same direction add & opposite direction subtract.