Which type of energy is in campfire WOOD?
potential energy (wood stores energy until it is burned)
Food, wood, and gasoline are examples of ________.
Fuel (they have to be burned to be useful)
Gasoline is a type potential energy. When it is consumed (used up) by a car, the potential energy is converted into ____________ energy and __________ energy.
Thermal energy and Kinetic energy
Wood is a type of potential energy. When it is burned, the potential energy is CONVERTED into __________ and ___________.
thermal energy (het) radiant energy (light)
When fuel is burned, it can be converted into many types of energies. Which form of energy is fuel MOSTLY converted to?
Thermal energy- most of the energy from BURNING fuel becomes heat.
Thermal energy (heat) ONLY flows from _____________ to ________________ temperatures.
High to Low
(Only from WARM to COOL)
How will you know when an object has transferred heat?
the temperatures will change (colder objects will get warmer AND warmer things will get colder)
Heat transfers until objects have _________________________
the same temperature (thermal equilibrium)
What does temperature measure?
the average kinetic energy of particles (it measures how much molecules vibrate in a certain material)
What is heat and when is heat felt?
a form of energy (thermal energy) that exists when objects have uneven temperatures so the energy tries to even out. You feel heat when your hand touches something that has more energy or less energy than your hand.
A wave transfers _____________ but not ________________.
Transfers ENERGY but not MATTER.
waves send energy without moving materials.
When heat transfers from hot to cold objects by RADIATION, the energy travels through ______________
empty space, without touching.
On a warm day, it is better to wear _________________ colored clothing because radiation is _______________.
light-colored clothing
radiation is REFLECTED (white reflects all colors)
____________ colors _____________ radiation, which is why it gets warmer quickly
darker colors
absorbs radiation (black absorbs all colors)
Which types of oven uses radiation ? (may be more than one answer)
a) solar cooker
b)conVENTional oven
c) conVECtion oven
A) solar cooker
B) Conventional oven (no fans in this oven)
During conduction, heat is transferred from hot to cold objects by _______________ between the objects.
direct contact/ touching
A metal object transfers heat from one end to another end by conduction. What do atoms do to transfer the heat?
atoms collide (bump into each other) but they don't move around. The atoms bump into other atoms that are nearby.
Which types of matter can heat transfer by CONDUCTION? (liquids, gases, solids?)
CONDUCTION can happen in ANY types of matter (solids, liquids, and gases)
Why is air a good insulator?
Air particles are far apart and moving around quickly. It is hard for the the particles to bump into each other.
When you hold a cold drink in your hand, heat transfers by conduction.
Which correctly describes the way the heat transfers?
a) the coldness from the drink transfers into the hand
b) the heat from your hand transfers to the drink
B) the heat from your hand transfers to the drink.
Can air be a fluid?
YEs, fluids are liquids AND gases.
Which state of matter does CONVECTION occur in? (solids, liquids, gases)
ONLY liquids and gases (fluids)
NO SOLIDS- too dense!
How does heat transfer by convection?
particles move around until they are all mixed
hot particles RISE
Cool particles SINK
What does density have to do with temperatures? how does the density change when temperatures are high or low?
HIGH temperatures make particles LESS DENSE
LOW temperatures make particles MORE DENSE
A CONVECTION oven is the most efficient type of oven because it uses all 3 types of heat transfer.
How does a CONVECTION oven use all 3 types of heat transfer to cook food? (you MUST explain all 3 to get the points)
radiation-
conduction-
convection-
radiation- the heated coils send energy out in all directions (without touching the food) and gets on the outside of the food and pan
conduction- The hot pan touches the bottom part of the food and cooks it. The top part of the food is hot and conducts heat towards the center.
convection- the hot air in the oven moves around by rising and sinking. Also, a fan helps the air to circulate and cook the food.