What direction does heat flow spontaneously (happening apparently)?
cold → hot
hot → cold
What is temperature compared to thermal energy (difference)?
Temperature: overall or random amount of energy/heat (°F, °C, °K) , Thermal Energy: directly measured (Joules)
Temperature: directly measured (°F, °C, °K) , Thermal Energy: overall or random amount of energy/heat (Joules)
Temperature: directly measured (Joules) , Thermal Energy: overall or random amount of energy/heat (°F, °C, °K)
Temperature: overall or random amount of energy/heat (Joules) , Thermal Energy: directly measured (°F, °C, °K)
Is work 100% efficient?
Yes; it is ALWAYS lost
Yes; it is NEVER lost
No; friction gets ALL of the energy lost
No; friction gets SOME of the energy lost
What is conduction?
Energy transferred by 2 things TOUCHING
Energy transferred through the movement of liquid or through CURRENTS
Energy transferred from an energy source and DOESN'T have to travel through MATTER
What is radiation?
What is convection?
What is thermodynamics?
The study of heat and thermal energy
The study of conversions between heat and other forms of energy
The study of particle movement
What is the 1st law of thermodynamics?
We can never reach absolute zero
Energy con never be created or destroyed and therefore must be conserved
Energy flows from hot → cold (to go from cold → hot, you must do work)
What is the 2nd law of thermodynamics?
What is the 3rd law of thermodynamics?
What does thermal energy depend on? (more than one answer)
temperature
volume
density
phase
mass
Most substances _____ when they freeze and _____ when heated. However, water _____ when it freezes _____ when it is heated.
contrast; expand; expand; contrast
contrast; expand; contrast; expand
contrast; contrast; expand; expand
expand; expand; contrast; contrast
What is specific heat?
When 2 different objects reaching the same temperature
Amount of heat needed to raise 1 gm of material 1°C
Amount of energy an object can sustain
Change in temperature
What is water's specific heat?
3.98 J/g°C ≈ 4 J/g°C
4 J/g°C (exactly)
2.98 J/g°C ≈ 3 J/g°C
1.98 J/g°C ≈ 2 J/g°C
Is water's specific heat high or low compared to other materials?
high; temperature raises less when energy is added
low; temperature raises less when energy is added
high; temperature raises more when energy is added
low; temperature raises more when energy is added
What is thermal equilibrium?
What do engines or motors do?
They are machines designed to make electricity by making a turbine turn
They are machines designed to make electricity by burning fuel
They are machines designed to convert mechanical energy into other forms of energy
They are machines designed to convert energy into mechanical energy
What is internal combustion?
Fuel sprayed into a cylinder which is then ignited and drives the piston (happening all together and inside motor)
Fuel that is ignited outside of the motor along with combustion
Burning happening inside a engine
What is external combustion?
Burning happening outside an engine
