Unit 5 Exam Study Guide

FIRST and FOREMOST...look here to see if you have all these notes.

• There are two main categories of energy:
• Kinetic= energy of motion ......This energy is doing work
  
• Potential= energy that is stored......This energy could do work but isn't doing work yet.
  

There are many different forms of energy and they all can be categorized as either kinetic or potential

• Thermal = energy of heat (kinetic)
• Nuclear = energy stored in atoms like in the sun (potential)
• Chemical = energy stored in chemical bonds like inside a battery or in a plant (potential)
• Sound = energy of sound waves (kinetic)
• Electrical = energy of moving electrons like through the wires in a flashlight (kinetic)
• Stored Mechanical = energy that is stored because of applying a force like a spring or rubber-band stretched out before you release them (potential)
  
• Motion/Mechanical = energy of things that are moving (kinetic)
  
• Electromagnetic/Radiant = energy in electromagnetic waves like sunlight, radio waves, and coming from lightbulbs (kinetic)
  

• Energy can not be created or destroyed, you can only change the version of the energy. This law is called the law of conservation of energy….we can only convert energy into another form.
• Heat energy or thermal energy can only move from warmer objects towards cooler objects
• Heat energy moves in one of three ways:
• Conduction: heat moving through objects because they are touching each other
  Exe. A handle on a pot gets hot even though it is not touching the burner, heat is transferred through the pot.
• Convection: heat transferred by the movement of currents in a fluid like water or air
  Exe. Hot water in a pot rises to the top and the cold water flows to the bottom. This also occurs in a room heated with hot water pipes (like our class). The pipes heat up the air near them, it rises to the top of the room, and the cool air is pushed to the floor (where it is heated and rises).
• Radiation: heat transferred by waves of heat energy
  Exe. When you step outside on a sunny day you feel heat from the sun even though you are not touching the sun. This is radiation. The same thing happens when your hand is near the stove and you feel heat.
  

Here are a few videos on energy to jog your memory and get you started studying...

Some Unit 5 Energy and Wave Help

I thought I would take some time to post the Energy notes that we took in class for anyone who was absent or those of you who have misplaced yours.



You also might want to review the basic parts of a transverse wave:
Keep in mind that the wavelength is not from the first crest to the last crest or from the first trough to the last trough, it is from a crest to the very next crest. So if a wave has more than one crest, you just would measure the distance from one crest to the next.

You should also be very familiar with one type of kinetic energy in particular: THERMAL ENERGY. Don't forget to review the guided notes that we wrote down about Thermal energy and Heat.

You should know the following for the Unit 4 Test:

• Speed = Distance ÷ Time and when we graph speed, distance is on the y-axis and time is on the x-axis...........Constant speed on a graph is a straight line.

• Acceleration = Speed ÷ Time.........Constant acceleration is a straight line on a speed vs. time graph
• Look at these Sample Graphs to see the difference:
  

• Velocity is speed plus the given direction of an object.

• Friction is when two surfaces rub against each other. Friction causes things to slow down, heat up, and wear out.

• Forces are pushes or pulls. They can add together (if they’re going the same direction) or subtract from each other (if they are acting in opposite directions). If they add together they generally form unbalanced forces. If they cancel each other out they form balanced forces.

• Unbalanced forces cause objects to change their motion. Like:

Speed up….Slow down….Start moving….Stop moving...Change Direction

• More mass, more inertia. Inertia is the tendency of an object to remain in motion or stay at rest.

• In order to test an idea you would:

Make a hypothesis: “IF I do _______________ , THEN I think _______________ will happen.”
Test the hypothesis: “I will change ____________ and record what happens. I will repeat it several times.
Analyze the data: “I wrote down my observations in this chart and then made a graph.”
Make conclusions based on facts: “When I did _______ the measurement changed to ________, this proves/disproves my hypothesis as correct.”