Calibrate the phototransistor.
How bright is it?
This activity has three different data collectors for light, each at a different scale, for different levels of brightness.
In this activity you will build a model greenhouse and explore light levels over the course of a day.
How does a greenhouse work?
Plants obviously grow outside, but often a greenhouse, which is a house for growing plants, is used to provide better conditions for plant growth than the outdoors. What conditions do you think typical plants like? Discuss this with your group members and record your thoughts and ideas below.
How do you think the conditions inside a greenhouse differ from the conditions outside? Think about different times of day and different seasons. Be prepared to discuss your thoughts with the class.
What are some of the physical features of a greenhouse, and how do these features create a good house for plants?
How do greenhouses affect the light levels for plants?
This unit addresses NSES standards for inquiry and physical science at grades 5-8 and NCTM standards on Algebra and Data Analysis at grades 6-8.
Before taking your data, what do you think the relative light levels will be for these times of day? On the Prediction Graph, indicate how you think light levels will vary over the course of the day. Be prepared to defend your graph.
In this activity you will build a model greenhouse and explore light levels over the course of a day.
How does a greenhouse work?
Plants obviously grow outside, but often a greenhouse, which is a house for growing plants, is used to provide better conditions for plant growth than the outdoors. What conditions do you think typical plants like? Discuss this with your group members and record your thoughts and ideas below.
How do you think the conditions inside a greenhouse differ from the conditions outside? Think about different times of day and different seasons. Be prepared to discuss your thoughts with the class.
What are some of the physical features of a greenhouse, and how do these features create a good house for plants?
How do greenhouses affect the light levels for plants?
This unit addresses NSES standards for inquiry and physical science at grades 5-8 and NCTM standards on Algebra and Data Analysis at grades 6-8.
Before taking your data, what do you think the relative light levels will be for these times of day? On the Prediction Graph, indicate how you think light levels will vary over the course of the day. Be prepared to defend your graph.
By using a temperature sensor, we can relate changes in sunlight to the temperature of the air being trapped in a container.
How is the atmosphere like a greenhouse?
The greenhouse effect is the name scientists use to describe how heat can build up in the earth’s atmosphere.
A majority of the energy from the sun arrives at the earth as visible radiation. This energy passes through our atmosphere and warms the surface of the earth. The warmed surface re-emits radiation but this radiation is not visible as it is in the infrared. Some of this infrared radiation is absorbed by our atmosphere. Our atmosphere absorbs more of the infrared radiation when water vapor, carbon dioxide, and methane are present. The more readily the infrared is absorbed, the greater the net energy gain from sunlight.
The effect of this process was examined using a model in the Greenhouse gases activity. In this activity you will measure the phenomenon in a real greenhouse setting. A glass enclosure — a real greenhouse — works in the same way as the atmosphere to capture heat from sunlight.
This activity addresses NSES standards for earth and space science and inquiry at grades 5-8
(http://books.nap.edu/readingroom/books/nses/6d.html#es).
Ordinary glass or clear plastic will transmit light but absorb infrared radiation. Knowing this, predict what will happen to the temperature under these two conditions:
a) container in sunlight without the cover;
b) container in sunlight with the plastic cover.
Draw your prediction on the graph below. Imagine that you will collect temperature data in sunlight for 20 minutes. For the first 10 minutes the container will have no cover. For the second 10 minutes the container will be covered with plastic. If you are indoors, the sun will be replaced by a bright light. Make the same prediction for that situation. You will need to move the time axis to include 1200 seconds (20 minutes) by clicking and dragging on the axis.
Try the same experiment with a light-colored material in the container, such as sand or sugar or salt. Does it make a difference? Why?
By using a temperature sensor, we can relate changes in sunlight to the temperature of the air being trapped in a container.
How is the atmosphere like a greenhouse?
The greenhouse effect is the name scientists use to describe how heat can build up in the earth’s atmosphere.
A majority of the energy from the sun arrives at the earth as visible radiation. This energy passes through our atmosphere and warms the surface of the earth. The warmed surface re-emits radiation but this radiation is not visible as it is in the infrared. Some of this infrared radiation is absorbed by our atmosphere. Our atmosphere absorbs more of the infrared radiation when water vapor, carbon dioxide, and methane are present. The more readily the infrared is absorbed, the greater the net energy gain from sunlight.
The effect of this process was examined using a model in the Greenhouse gases activity. In this activity you will measure the phenomenon in a real greenhouse setting. A glass enclosure — a real greenhouse — works in the same way as the atmosphere to capture heat from sunlight.
This activity addresses NSES standards for earth and space science and inquiry at grades 5-8
(http://books.nap.edu/readingroom/books/nses/6d.html#es).
Ordinary glass or clear plastic will transmit light but absorb infrared radiation. Knowing this, predict what will happen to the temperature under these two conditions:
a) container in sunlight without the cover;
b) container in sunlight with the plastic cover.
Draw your prediction on the graph below. Imagine that you will collect temperature data in sunlight for 20 minutes. For the first 10 minutes the container will have no cover. For the second 10 minutes the container will be covered with plastic. If you are indoors, the sun will be replaced by a bright light. Make the same prediction for that situation. You will need to move the time axis to include 1200 seconds (20 minutes) by clicking and dragging on the axis.
Try the same experiment with a light-colored material in the container, such as sand or sugar or salt. Does it make a difference? Why?
How does energy change from one form to another?
In this activity energy will be moved from batteries to holiday bulbs and resistors, and the temperature changes will be monitored.
When you use a flashlight, several energy transformations take place. List all of the forms of energy that are involved when you connect a battery to a light bulb. What forms of energy are in the battery, the wires, and the bulb? Where does the energy go at the end of the process?
You will measure how fast the light bulb heats up when you connect it to the battery, under various conditions. Picture a graph where you turn on the bulb for 30 seconds, then turn it off for 30 seconds. Here are the four conditions:
A. by itself, with just the clear tape holding on the temperature sensor.
B. surrounded by aluminum foil.
C. buried in a lump of clay.
D. The final test will be to heat up a resistor that is buried in a lump of clay, along with the temperature sensor.
For condition A, draw how you think the temperature graph will look, using the graph prediction tool. Then describe in words how the other three graphs will be different from this.
What can you conclude about whether light bulbs give off mostly heat energy or mostly light energy? Why?
Try other ways of enclosing the light bulb. Turn it on and off for a fixed time and compare the rates of heating and cooling.
How does energy change from one form to another?
In this activity energy will be moved from batteries to holiday bulbs and resistors, and the temperature changes will be monitored.
When you use a flashlight, several energy transformations take place. List all of the forms of energy that are involved when you connect a battery to a light bulb. What forms of energy are in the battery, the wires, and the bulb? Where does the energy go at the end of the process?
You will measure how fast the light bulb heats up when you connect it to the battery, under various conditions. Picture a graph where you turn on the bulb for 30 seconds, then turn it off for 30 seconds. Here are the four conditions:
A. by itself, with just the clear tape holding on the temperature sensor.
B. surrounded by aluminum foil.
C. buried in a lump of clay.
D. The final test will be to heat up a resistor that is buried in a lump of clay, along with the temperature sensor.
For condition A, draw how you think the temperature graph will look, using the graph prediction tool. Then describe in words how the other three graphs will be different from this.
10.
11. Repeat steps 2 – 6.
What can you conclude about whether light bulbs give off mostly heat energy or mostly light energy? Why?
Try other ways of enclosing the light bulb. Turn it on and off for a fixed time and compare the rates of heating and cooling.