Activity Title: 'A Lifting Experience'

Subject Area: Math

Grade Levels: 5th + 6th

Students will explain the scientific meaning of work and use a formula to calculate the amount of work done in various situations.

Colorado Standard(s) and/or Benchmark(s) addressed in this activity:

National Standard(s) and/or Benchmark(s) addressed in this activity:

Vocabulary: Newton Force Joule Work Mechanical advantage   Materials: journal to record data scissors string meterstick book or objects to test spring scale

Preparation:

1. Cut a piece of string 1m long.
2. Have each student select two or more objects to test. Student will suspend objects individually from a spring scale, i.e., book, shoe, etc.

Procedure:

1. Have students determine what is force (push or pull on an object), newton (the international unit of force), work (when an object moves as a result of a force acting upon it), joule (a unit of work), mechanical advantage (the number of times a machine multiplies the effort/force- MA=distance divided by height).
2. Students will record that one joule of work is performed when a force of one newton moves an object a distance of one meter, i.e., Work=Force x distance.
3. Students measure the force required to lift various objects a premeasured distance, then calculate the amount of work that was done.
4. Distribute a spring scale, string and a meterstick to student groups. Demonstrate how to use a spring scale, calibrating if needed if it fails to point to 0 newtons with no load attached.
5. Explain that students will lift a variety of objects with the spring scale, note the newtons of force required to lift each object, measure the distance that each object is lifted, and then calculate the amount of work accomplished.
6. Create a chart* by columns listing the ‘Object’, ‘Force’ (newtons), ‘Distance’ (meters), and ‘Work’ (joules) at the top of the columns.
7. Weigh each object from the spring scale, and then record each weight in the ‘Force’ column.
8. As you raise each object, record the height an object is lifted in the ‘Distance’ column.
9. Find the amount of work done on each object by multiplying the weight of an object by the distance it was lifted. Record the results in the ‘Work’ column.

* Students can create their own chart in journals or use our prepared worksheet.

 

Analyze and Conclude:

1. Describe the relationship between the weight of an object and the work that is done to lift it.
2. Describe the relationship between the height that an object is lifted and the work that is done to lift it.
3. If an object weighing (3) newtons is lifted (2) meters high, then another object weighing (6) newtons is lifted (1) meter high, how is the amount of work done compared from one object to the other? How do you know?

TIP: students can either write answers in journals or use our prepared worksheet.

 

Assessing Student Performance:

1. Did the students measure accurately the weight of different objects?
2. Did they use numbers accurately as they made their calculations? Was the formula W=F x d used properly?
3. Was data recorded carefully?
4. Did students infer the relationship between the weight of an object, the distance the object is moved, and the amount of work done to move the object? Did they understand that changing the weight of an object or the distance that it is moved changes the amount of work done on the object?

Assessment Rubric:

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