Sliding Away

Directions: Use the following information to answer questions 1 through 8.

Elizabeth and Billy live in a mountainous area where landslides occur. They noticed that landslides are more common on some steep hills than other steep hills. Elizabeth and Billy wondered if some types of Earth materials tend to slide down steep hills more than others. They conducted the following investigation, using a ramp to model the slope of a hill.

Question: How does the type of Earth material (gravel, sand, and silt) affect the ramp angle at which the Earth material will slide?

Hypothesis: Sand will slide at the lowest ramp angle because sand is made of loose grains.

Materials:

clear, plastic box with an open top

Earth materials: dry gravel, dry sand, and dry silt

scale

protractor

ramp

Sliding Away

Procedure:

1.      Make sure the ramp is clean and dry before each trial.

2.      Fill the plastic box with 4.9 newtons (N) or 1.1 pounds of gravel.

3.      Carefully place the plastic box open side down on the middle of the ramp when the ramp is flat on the table as shown in the Investigation Setup diagram.

4.      Slowly lift one end of the ramp until the plastic box filled with gravel starts to slide down the ramp as shown in the Investigation Setup diagram.

5.      Measure and record the angle at which the plastic box filled with gravel starts to slide as Trial 1.

6.      Repeat steps 1 through 5 as Trials 2 and 3 for the gravel.

7.      Repeat the investigation using sand and then silt.

8.      Calculate and record the average ramp angle for each Earth material.

Data:

Sliding Away

5    Write a conclusion for this investigation.

 In your conclusion, be sure to:

• ·         Answer the investigative question.

• ·         Include supporting data from the Earth Material vs. Ramp Angle table.

• ·         Explain how these data support your conclusion.

Sliding Away

Lifting a Load

Directions: Use the following information to answer questions 9 through 16.

James and Heidi needed to lift a heavy box up to a storage loft. The box was too heavy for them to lift together, so they designed a way to lift the box. The stages of their design process are described below.

Problem: Lift a heavy box up to a storage loft.

Gather Information: The box weighs 1,500 newtons (N) or 337 pounds. James and Heidi each weigh 500 N, or 112 pounds. The loft is 2 meters (m) high. A strong, 4.0-m long board and a triangular-shaped wooden block are available.

Explore Ideas:

Ö        Use the board as a ramp and slide the box up by pushing from below.

Ö        Use the board and block as a lever system with the board as the lever and the block as
the fulcrum.

Plan Summary: Lift the box with a lever system because Heidi’s weight can be the input force.

Steps to Do the Plan:

1.      Slide the box onto one end of the lever.

2.      Place the fulcrum 1 m from the box as shown in the Diagram of Solution (Before lifting).

3.      Heidi carefully stands on the other end of the lever, 3 m from the fulcrum as shown in the Diagram of Solution (After lifting).

Diagram of the Solution

Lifting a Load

Test Solution: Measure and record Heidi’s input force and distance moved. Measure and record the lever output force and distance moved.

Test Results:

Lifting a Load

14 Explain why the lever system allows Heidi’s 500-N weight to lift the 1,500-N box.

In your explanation, be sure to:

·        Give details about the distances Heidi and the box moved.

·        Describe how a 500-N force can become a 1,500-N force in the lever system.

Lifting a Load

15 Describe the function of the board in the lever system, and the properties of the board that enable the system to work.

In your description, be sure to:

·         Describe the function of the board in the lever system.

·         Identify and give details about two physical properties of the board that enable the
system to work.

Lifting a Load

16 The lever system James and Heidi designed did not lift the box high enough. Describe how you would scientifically design a new solution or redesign their solution to the problem using some or all of the materials and tools listed below.

Only these materials and tools may be used: several more identical 4-m long boards; several more triangular shaped wooden blocks; rope, nails, bolts, and nuts; hammer, saw, wrench, wood drill, pulleys, meter sticks, paint brush and a scale to measure force or weight.

Be sure to describe the following stages of your design process:

·         Gather Information: Describe the information needed and how to collect that information.

• Explore Ideas: Describe several ideas including any useful scientific concepts.

·         Plan Summary: Write a summary including reasons for choosing this solution.

·         Steps to Do the Plan: Write the steps including all the materials used in the Plan Summary and in the Diagram of Solution.

·         Diagram of Solution: Make a labeled diagram.

·         Test Solution: Describe the process to measure or observe how well this solution may solve the problem.

Lifting a Load