Convection currents lab
Convection currentsMaterials Needed:
1 Clear Plastic Box
1 Pipette
10 Styrofoam Cups
Pre-Lab Questions
1. Match the term below with its definition.
Conduction- the transfer of heat by touching
Convection- the transfer of heat in a fluid (air or water) that rises due to the density differences
Radiation- the transfer of heat by infrared waves
2. If one beaker contains 100 ml of cold water, and another contains 100 ml of hot water, which beaker contains more molecules? Explain.
The cold beaker would hold more molecules that reason being cold water is denser than warm water, the denser the material, the more molecules it has.
3. Which water, hot or cold, would have the higher mass? Which would have the higher density? (Hint: Remember, density = mass per unit volume d = g/cm3)
Cold water would have the higher mass and it would also be denser.
4. As you open a refrigerator door, what happens to the air inside?
The cold air comes out of the bottom of the fridge, heats up the air around, rises again.
5. As you lift the lid from a pot of soup, do the gases that escape rise from the pot, or sink around its base? Why?
the steam and hot gasses rise from the opened pot.
6. If you swim to the bottom of a pool and place a cork on the bottom, will the cork stay in place? Why or why not? Explain.
That all depends on the density, hmmmm i think i'll say no
7. Both air and water are fluids. What will happen to an area with a fluid that becomes warmer than the surrounding fluid?
It'll rise above the surrounding air, cool down and sink again.
8. Atmospheric pressure is the pressure exerted on earth by the force of gravity pulling the air towards the earth's surface. Where air is rising from the surface, will the atmospheric pressure be increased or decreased?
The atmospheric pressure would be decreased.
For the first setup, we filled the tub with normal, cool water, then put three dots of red food-dye, we tried to make it as even as possible. Then boiled some water put it in a foam cup that went directly underneath the middle dot of dye. We watched the red dye in the middle rise, then it gradually cooled and sank down to mix with the other dots of dye at the bottom of the tank.
1 Clear Plastic Box
1 Pipette
10 Styrofoam Cups
Pre-Lab Questions
1. Match the term below with its definition.
Conduction- the transfer of heat by touching
Convection- the transfer of heat in a fluid (air or water) that rises due to the density differences
Radiation- the transfer of heat by infrared waves
2. If one beaker contains 100 ml of cold water, and another contains 100 ml of hot water, which beaker contains more molecules? Explain.
The cold beaker would hold more molecules that reason being cold water is denser than warm water, the denser the material, the more molecules it has.
3. Which water, hot or cold, would have the higher mass? Which would have the higher density? (Hint: Remember, density = mass per unit volume d = g/cm3)
Cold water would have the higher mass and it would also be denser.
4. As you open a refrigerator door, what happens to the air inside?
The cold air comes out of the bottom of the fridge, heats up the air around, rises again.
5. As you lift the lid from a pot of soup, do the gases that escape rise from the pot, or sink around its base? Why?
the steam and hot gasses rise from the opened pot.
6. If you swim to the bottom of a pool and place a cork on the bottom, will the cork stay in place? Why or why not? Explain.
That all depends on the density, hmmmm i think i'll say no
7. Both air and water are fluids. What will happen to an area with a fluid that becomes warmer than the surrounding fluid?
It'll rise above the surrounding air, cool down and sink again.
8. Atmospheric pressure is the pressure exerted on earth by the force of gravity pulling the air towards the earth's surface. Where air is rising from the surface, will the atmospheric pressure be increased or decreased?
The atmospheric pressure would be decreased.
For the first setup, we filled the tub with normal, cool water, then put three dots of red food-dye, we tried to make it as even as possible. Then boiled some water put it in a foam cup that went directly underneath the middle dot of dye. We watched the red dye in the middle rise, then it gradually cooled and sank down to mix with the other dots of dye at the bottom of the tank.
For the second Format of the Tank, we put 2 heated foam cups under the left and right dye, and watched the dye rise at the sides, it then fell
Our team's last tank setup (C) was when we put a blue dyed ice cube at the left side of the tank, then put two heated cups under the center and right pools of dye. The cube not only sped up the cooling as the red water rose, it showed the cold blue water sink to the left side of the tank pretty fast
Post-Lab Questions:
1) During the lab, what effect did the cups of hot water have on the density of the water directly above them?
It made the water less dense, and warmer than the surrounding water.
2) What happened as a result of this change?
The red dye began to rise slowly
3) A house has a glass "sun space" attached to its south side, which is just a space all around the house, next to the outside wall that holds air. Vents allow air to flow from the house into the sun space, and vice versa. Describe the direction air flow as the air in the sun space is warmed by the Sun.
The hot air would go up, and the cold air would go to bottom
4) You may have noticed convection cells in a pot of boiling macaroni. Describe the direction of water flow in the pot. The hottest part of the burner is beneath the center of the pot.
The water flow will go up from the center and then sink to the edges, creating a circular motion.
5) Which situation would result in a decrease in atmospheric pressure at the earth's surface? Identify the correct answer.
A) air gets hot and begins to rise
6) Go back to the three diagrams you constructed in your lab. label the spots in each diagram that became areas of lower pressure.
Setup 1: In the middle red dye.
Setup 2: athe left dye and right dye.
Setup 3: In the middle and right dye.
7) Above which area would the air become hotter in the afternoon? Identify the correct answer.
A- a parking lot with blacktop pavement.
8) Above which area would you find the lowest air pressure?
A- the parking lot.
9) Based on this arrangement, would you expect a breeze to blow toward the parking lot, or away from it? Why?
A breeze would blow toward the parking lot.
10) From your knowledge of onshore and offshore breezes, explain why the wind would blow in from the sea toward the land during the afternoon.
the low pressure goes to the sea, high pressure go to the land
11) A "monsoon effect" may happen in the summer as air over a continent becomes much warmer than air over the ocean. Fill in the blanks in the following statements:
A) air over the continent becomes hotter, it will begin to rise.
B)tis causes lower pressure over the continent.
C)The flow of air will be toward the center of the continent.
12) Think globally now. Which region in our atmosphere is heated most intensely by the sun? Identify the correct answer.
C- the equator.
13) As air near the equator rises, does this become an area of higher or lower pressure?
This becomes an area of lower pressure.
14) What moves in to replace the rising air?
Cooler air moves in to replace the rising air.
15) Number the following stages of atmospheric circulation (1-4) in the order in which they are most likely to occur.
16) If hot air rises, why is air that is closer to the Earth's surface warmer than the air high above it?
Conduction and the layers of the surface cause it to be warmer.
17) Wind is considered to be a form of "solar energy". Explain why.
Since the sun warms up the earth, this causes the earth to heat up the wind. An area of low pressure develops, and cold air begins to rise. after, wind comes in
Our team's last tank setup (C) was when we put a blue dyed ice cube at the left side of the tank, then put two heated cups under the center and right pools of dye. The cube not only sped up the cooling as the red water rose, it showed the cold blue water sink to the left side of the tank pretty fast
Post-Lab Questions:
1) During the lab, what effect did the cups of hot water have on the density of the water directly above them?
It made the water less dense, and warmer than the surrounding water.
2) What happened as a result of this change?
The red dye began to rise slowly
3) A house has a glass "sun space" attached to its south side, which is just a space all around the house, next to the outside wall that holds air. Vents allow air to flow from the house into the sun space, and vice versa. Describe the direction air flow as the air in the sun space is warmed by the Sun.
The hot air would go up, and the cold air would go to bottom
4) You may have noticed convection cells in a pot of boiling macaroni. Describe the direction of water flow in the pot. The hottest part of the burner is beneath the center of the pot.
The water flow will go up from the center and then sink to the edges, creating a circular motion.
5) Which situation would result in a decrease in atmospheric pressure at the earth's surface? Identify the correct answer.
A) air gets hot and begins to rise
6) Go back to the three diagrams you constructed in your lab. label the spots in each diagram that became areas of lower pressure.
Setup 1: In the middle red dye.
Setup 2: athe left dye and right dye.
Setup 3: In the middle and right dye.
7) Above which area would the air become hotter in the afternoon? Identify the correct answer.
A- a parking lot with blacktop pavement.
8) Above which area would you find the lowest air pressure?
A- the parking lot.
9) Based on this arrangement, would you expect a breeze to blow toward the parking lot, or away from it? Why?
A breeze would blow toward the parking lot.
10) From your knowledge of onshore and offshore breezes, explain why the wind would blow in from the sea toward the land during the afternoon.
the low pressure goes to the sea, high pressure go to the land
11) A "monsoon effect" may happen in the summer as air over a continent becomes much warmer than air over the ocean. Fill in the blanks in the following statements:
A) air over the continent becomes hotter, it will begin to rise.
B)tis causes lower pressure over the continent.
C)The flow of air will be toward the center of the continent.
12) Think globally now. Which region in our atmosphere is heated most intensely by the sun? Identify the correct answer.
C- the equator.
13) As air near the equator rises, does this become an area of higher or lower pressure?
This becomes an area of lower pressure.
14) What moves in to replace the rising air?
Cooler air moves in to replace the rising air.
15) Number the following stages of atmospheric circulation (1-4) in the order in which they are most likely to occur.
- Uneven heating
- Area of low pressure develops
- Convection
- Wind
16) If hot air rises, why is air that is closer to the Earth's surface warmer than the air high above it?
Conduction and the layers of the surface cause it to be warmer.
17) Wind is considered to be a form of "solar energy". Explain why.
Since the sun warms up the earth, this causes the earth to heat up the wind. An area of low pressure develops, and cold air begins to rise. after, wind comes in