Heat, usable energy, and speed Flashcards
Heat
Heat is the flow of thermal energy.
How does heat flow?
Heat always flows in the direction to reach a more stable state.
Results of this are:
*Thermal energy between two objects becomes more evenly distributed
*Heat always flows from the hotter object to the colder object
*The thermal energy of the hotter object drops by the same amount that the colder object gains.
Factors that determine heat flow:
- Temperature change
- Mass
- Material
Heat flow equation
Q=cmdeltat (specific heat * mass (g) *change in temperature)
Speed
Speed is the measure of linear motion. It is the distance traveled by an object divided by the time it takes to move.
Speed equation
v=d/t (distance (m)/ time (s)
Linear kinetic energy is higher when?
- The object moves faster
2. The object has more mass
Linear kinetic energy equation:
LKE= 1/2 mv^2 (mass (kg) * velocity)
Usable vs unusable energy
usable energy is energy available to do work, unusable energy is energy not available to do work.
Types of unusable energy:
- Sound
- Radiant
- Thermal
When energy changes forms:
some energy is always converted to unusable forms.
Two factors that matter for an energy source:
- The amount of energy
2. How much energy can be extracted
Minimizing energy loss:
- Minimize friction, air resistance, and other forms that convert to thermal, sound.
Minimizing friction:
- Use a lubricant
2. put space between objects
Minimize air resistance:
*Make the object(s) more aerodynamic.
