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In this activity you will investigate a simple machine called an Inclined Plane, which can be found in our everyday life activities.

Today, You Will Be Solving REAL Problems Like Scientists

You will be working in groups of 3 or 4. All of you will get to perform one or more tasks.

The Problem – “How Does An Inclined

Plane Help Us Move Things From

One Place To Another”?

Now State your Hypothesis about the problem in this activity, in the space below.

______

Materials – One rubber band, one piece of cardboard, 3 black cylinder shaped weights,(I used rod shaped ankle weights of 1lb each), a metric ruler, masking tape, a stack of thick books.

Procedures –

Part 1

  1. Rubber bands are already attached to 2 of your black cylinder weights. DO NOT REMOVE THEM.
  2. On the rubber band, a line is marked on each side.
  3. Each rubber band is 10 CENTIMETERS long, from the top of the weight to the ink line on the rubber band.
  4. Now, lay the weight down ON THE TABLE, and measure the distance from the top of the black weight to the blue line on the rubber band now. Is it 10 centimeters long?______
  5. With your two fingers just above the ink mark of the rubber band, hang the weight, and have one of your team partnersmeasure the length of the rubber band to the nearest ½ CENTIMETER. What happened to the rubber band when the weight was hanging down? ______
  6. Now, subtract 10 CENTIMETERS from the length of the stretched rubber band.
  7. Record this length in DATA TABLE 1.
  8. Why do you think you subtracted the 10 centimeters? ______

______

  1. Now using enough masking tape,tape the black weight with the rubber band to one WITHOUT the rubber band, side by side to each other.
  2. With your two fingers just above the ink mark of the rubber band, hang the TWO weights, and have a team membermeasure the length of the rubber band AGAIN to the nearest ½ CENTIMETER.
  3. Again, subtract 10 CENTIMETERS from the length of the stretched rubber band again.
  4. Record this NEW length in the proper space in DATA TABLE 1.
  1. Did the rubber band stretch more or less than the hanging SINGLE weight?______
  2. Why do you think that happened? ______

15. What FORCE do you think is causing the black weight to stretch?

Part 2

  1. Now, stack about 2-5 books of your choiceon your table.
  2. Place the cardboard on the edge of the book stack as seen in the picture on the next page. This SLOPE, will make an inclined plane, which we will study.
  3. Using the masking tape, fasten the cardboard to the books and the table to prevent it from sliding.

Stack

Pull weight

Up the slope of

Books

  1. Now the tough part begins!Using the single weight with your rubber band attached, and placed at the BOTTOM of the inclined plane.
  2. Have ONE member, with their two fingers above the ink mark again, SLOWLY, AND STEADILY, drag the weight UP the INCLINED PLANE.(NOT TOO FAST)
  3. Have one member HOLD THE CARDBOARD gently to prevent it from sliding.
  4. Have another team memberMEASURE the length of the rubber band to the ½ NEAREST CENTIMETER, as it is pulled SLOWLY up the inclined plane,.
  5. Do this TWO more times, each time SUBTRACT 10 centimeters from the length. This length is the amount the rubber band was stretched going UP the INCLINED PLANE.
  6. RECORD the 3 trials in the proper places in DATA TABLE 2.

Part 3

  1. Now, using the twoTAPED weights, place your two fingers AGAIN, above the ink mark, and drag the TWO weights STEADILY up the incline.
  2. Have a team membermeasure the stretched rubber band AGAIN to the nearest ½ CENTIMETER.
  3. As before, have some one hold the incline plane gently to prevent it from slipping.
  4. SUBTRACT 10 centimeters from the length you chose. This length is the amount the rubber band was stretched going UP the INCLINED PLANE.
  5. Do this TWO MORE times, andrecord the 3 trials in the proper spacesin DATA TABLE 2

Your Observations -

Data Table 1

With Weights Hanging Down

Number of Weights Used / Length The Rubber
Band Stretched
1 Weight
2 Weights

Data Table 2

Dragging Weights Up Inclined Plane

Number of
Weights Used / LengthThe Rubber Band Stretched
1 Weight / Trial 1
Trial 2
Trial 3
2 Weights / Trial 1
Trial 2
Trial 3

Conclusions, and Questions for discussion.

  1. Why was your group asked to subtract the 10 centimeters every time you measured the amount the rubber band was stretched? ______

______

  1. Compare the difference the rubber band was stretched between lifting the weights straight up, and dragging them up the incline plane. Which required more force?______
    ______
  2. Why do you think so? ______
  3. Does this agree with your HYPOTHESIS at the start of the lab activity? ______
  4. What was the name of the FORCE you were working against when you lifted the weight, or dragged it up theinclined plane?______
  5. Why do you think you were asked to perform more than one trial when dragging the weight up the slope? Were all you’re your measurements ______
  6. Why didn’t ALL the groups have the same values when pulling the SINGLE, and DOUBLE weights up the inclined plane? Can you give some REASONS why this was true.

______

  1. What are some things you COULDhave done to make it easier to pull the weight UP the inclined plane? ______

______

______

  1. Discuss applicationsand uses of an inclined plane.

______

______

Expectations From This Activity

  1. Use scientific thinking processes to conduct investigations and build

Explanations by observing, communicating, comparing, organizing, and

Relating with each other.

  1. Compare and contrast use and disuse of inclined plane.
  2. Children should understand the fundamentals of the “Scientific Method”.
  3. Children should understand the meaning of a hypothesis,

and be able to apply its use in this activity.

  1. The children should be able utilize measurements as related to scientific experimentation.
  2. The children should be able to understand why trials are used

inlaboratory situations, and learn to discard measurements which depart from the other more consistent measurements.

  1. The children should be able to relate the stretching of the

rubber band as a simple method to measure forces, such as gravity, or weight.

8 .The children should be able to relate how theangle or lengthof the slope affects the force required to move the weights.

  1. The children should be able to explain why the results using

one and two weights were different to move the objects up the incline.

  1. The children should be able apply the incline plane to uses in

their everyday lives.

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