Ch6_MalleyJ

Ch6_MalleyJ

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Internal vs. External Forces

 * Forces can be categorized based upon whether or not their presence is capable of changing an object's total mechanical energy
 * External forces: include the applied force, normal force, friction force, air resistance force, tension force, and normal force.
 * Internal forces: include force of gravity, and force of spring.
 * The importance of categorizing a force as being either internal or external is related to the ability of that type of force to change an object's total mechanical energy when it does work upon an object
 * If the work is positive work, then the object will gain energy
 * If the work is negative work, then the object will lose energy
 * Nonconservative forces: external forces that are capable of changing the total mechanical energy of an object
 * Description of motion questions results (PE to KE or KE to PE?): 4/5
 * When work is done by external forces, the total mechanical energy of the object is altered
 * The work that is done can be positive work or negative work depending on whether the force doing the work is directed opposite the object's motion or in the same direction as the object's motion
 * Description of motion questions results (+ or - work?): 5/6
 * A horizontal force can never change the potential energy of an object because they cannot cause vertical displacement

Power Costs Activity

 * Data**:
 * Equations Used**:

According to this, I'm really not costing my mom all that much per day. However, I didn't include a lot of items, like my laptop charger, the TV, and lights that I use daily. Turning them off definitely saves a lot of money and power, even if it's only a small amount. Everything adds up. My mom always tells me to turn off the lights when I leave a room, and by looking at the electrical bill, I can tell why she would want to save anywhere she can. Although a kW is less than a penny, and I use less than a penny with these ten listed items per day, I live in a family of three - we use a fair amount of energy. It's pretty expensive overall according to the bill, and I know that I probably account for my fair share of it.