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Weathering and Erosion

Investigation 2 – Lab

 

 

 

 

 

 

 

MINDSET

This Investigation is designed to allow you to:

  • model erosion,
  • investigate the factors that affect erosion, and
  • investigate the effects of erosion.

BE PREPARED

Student Preparation for the Investigation includes having students gather the following materials. This preparation takes place on lab day after student lab groups have settled at their assigned lab tables.

Note: The materials are listed in your SDR. They are also listed below for your reference.

  • (1) triple beam balance
  • (1) paint tray
  • (1) liter pitcher filled with 600 g of sand
  • (2) 1000ml graduated cylinders filled with 1.5 liters of water
  • (2) shoebox containers
  • (1) support rod and base
  • (1) support ring
  • (1) test tube clamp holder
  • (1) test tube, dual, prong holder
  • (1) metric ruler
  • (5) pieces of obsidian pitchstone
  • (5) jacks
  • (1) lab marker
  • (1) roll of masking tape
  • (1) lab scoop

Direct one student from each lab group to collect the materials listed in their SDRs.

INVESTIGATE

  • Your group will conduct four trials to investigate erosion.
  • Any sand that spills onto the lab table can be easily swept into one of the containers by using the straight edge of the metric ruler.
  • Reflect on the PreLab video as you move through the procedural steps.
  • During the Experiment, every procedural step is important. If one step is skipped, data can become invalid. To help you keep on track, read each step thoroughly, complete the step, then check it off (Read it – Do it – Check it).
  • Complete all of the procedural steps in your SDR.

Note: The procedural steps are listed below for your reference. 

  1. In this Investigation, you will model how different factors can affect erosion.
  2. Using the triple beam balance, determine the mass of one of the shoebox containers. Use the lab marker and write the mass on a piece of masking tape. Place the tape on one of the long sides of the container.
  3. Record the mass of the container in Table A at the end of the Investigation.
  4. Use the picture below to help with the following procedure.

WE 2

    1. Use the lab scoop to pour the moistened sand from the liter pitcher into the trays. Use the lab scoop to spread the sand and smooth its surface.
    2. Use the metric ruler to adjust the support ring so it is 7cm above the base of the stand.
    3. Use the metric ruler to adjust the test tube clamp so it is 15cm above the base of the stand.
    4. Clamp the rear edge of the trays into the clamp and rest the trays on the support ring.
    5. Support the front edge of the trays on the container.
    6. The front edge of the trays should form a “V” shape that is centered on the notch. The “V” should direct water into the container.
    7. Completely moisten the sand. Fill the graduated cylinder to the 1000ml mark with water and carefully pour the water into the top of the trays. Let the water flow down the sand into the container.
    8. Loosen the test tube clamp and remove the trays. Pour any water remaining in the top of the trays into the container.
    9. Let the sand in the container settle for several seconds and pour all the water back into the graduated cylinder. Add more water so the level is at the 1000ml mark.
    10. Use the scoop to return the sand to the trays. Use the scoop to spread the sand and smooth its surface.
    11. Reposition the trays in the clamp and on the support ring. Place the container back under the trays so the front edge reforms the “V” shape.

 

Trial 1

  1. In this Trial, you will model the effect of erosion on the soil of a slope.
  2. Slowly pour all 1000ml of water into the top of the trays. Let the water flow down the sand into the container.
  3. Loosen the test tube clamp and remove the trays. Pour any water remaining in the top of the trays into the container.
  4. Let the sand in the container settle for several seconds and pour all the water back into the graduated cylinder. Add more water so the level is at the 1000ml mark.
  5. Use the triple beam balance to determine the mass of the container and the sand.
  6. Record the mass in column 3 of Table A for Trial 1. Table A is located at the end of Trial 4.
  7. Use the scoop to return the sand to the trays. Use the scoop to spread the sand and smooth its surface.

Note: All water should be carefully poured into the top of the trays so that water slowly spills and runs over the sand. All 1000ml of water should be added slowly and should take approximately ten seconds.

 

Trial 2

  1. In this Trial, you will model the effect of erosion of soil on a steeper slope.
  2. Use the picture below to help with the following procedure.

WE 2A

    1. Use the metric ruler to adjust the support ring so it is 10cm above the base of the stand.
    2. Use the metric ruler to adjust the test tube clamp so it is 18cm above the base of the stand.
    3. Clamp the rear edge of the trays into the clamp and rest the trays on the support ring.
    4. Support the front edge of the trays on the container.
    5. The front edge of the trays should form a “V” shape that is centered on the notch. The “V” should direct water into the container.
  1. Slowly pour all 1000ml of water into the top of the trays. Let the water flow down the sand into the container.
  2. Let the sand in the container settle for several seconds.
  3. Slide the second container under the trays replacing the first container so the trays are supported on the second container.
  4. Pour all the water back into the graduated cylinder. Add more water so the level is at the 1000ml mark.
  5. Use the triple beam balance to determine the mass of the container and the sand.
  6. Record the mass in column 3 of Table A for Trial 2.
  7. Use the scoop to return the sand to the trays. Use the scoop to spread the sand and smooth its surface.
  8. Slide the first container back under the trays replacing the second container so the trays are supported on the first container.

Note: All water should be carefully poured into the top of the trays so that water slowly spills and runs over the sand. All 1000ml of water should be added slowly and should take approximately ten seconds.

Trial 3

  1. In this Trial, you will model the effect of erosion of soil when rocks are placed on a slope.
  2. Place 5 pieces of obsidian pitchstone on the sand where you think that they will decrease erosion. Push the pieces firmly into the sand.
  3. Slowly pour all 1000ml of water into the top of the trays. Let the water flow down the sand into the container.
  4. Let the sand in the container settle for several seconds.
  5. Slide the second container under the trays replacing the first container so the trays are supported on the second container.
  6. Pour all the water back into the graduated cylinder. Add more water so the level is at the 1000ml mark.
  7. Use the triple beam balance to determine the mass of the container and the sand.
  8. Record the mass in column 3 of Table A for Trial 3.
  9. Use the scoop to return the sand to the trays. Use the scoop to spread the sand and smooth its surface.
  10. Slide the first container back under the trays replacing the second container so the trays are supported on the first container.

Trial 4

  1. In this Trial, you will model the decrease of erosion of soil when vegetation grows on a slope.
  2. Place 5 jacks on the sand where you think they will affect erosion. Push the jacks firmly into the sand.
  3. Slowly pour all 1000ml of water into the top of the trays. Let the water flow down the sand into the container.
  4. Let the sand in the container settle for several seconds.
  5. Slide the second container under the trays replacing the first container so the trays are supported on the second container.
  6. Pour all the water back into the graduated cylinder.
  7. Use the triple beam balance to determine the mass of the container and the sand.
  8. Record the mass in column 3 of Table A for Trial 4.
  9. Loosen the test tube clamp and remove the trays. Place the trays on the lab table.

 

CLEAN UP

Work with your group to clean your lab bench after your experiments.