Grade 07 Science - EC: S7.C.3.1.3
Grade 07 Science - EC: S7.C.3.1.3
Continuum of Activities
The list below represents a continuum of activities: resources categorized by Standard/Eligible Content that teachers may use to move students toward proficiency. Using LEA curriculum and available materials and resources, teachers can customize the activity statements/questions for classroom use.
This continuum of activities offers:
- Instructional activities designed to be integrated into planned lessons
- Questions/activities that grow in complexity
- Opportunities for differentiation for each student’s level of performance
Grade Levels
7th Grade
Course, Subject
Science
Related Academic Standards / Eligible Content
Activities
- List the 6 simple machines.
- What is a compound machine?
- Explain how the input force is related to the output force when using a lever.
- Explain how the height and length of an inclined plane affect its mechanical advantage.
- Your aunt wants to move a piano to the second floor of her home. What type of pulley system would you recommend using: fixed, moveable, or block and tackle? Explain your answer in terms of mechanical advantage.
Answer Key/Rubric
- The 6 simple machines are:
- Lever
- Wheel and axle
- Screw
- Inclined plane
- Wedge
- Pulley
- A compound machine is a machine that is composed of two or more simple machines.
- Acceptable responses may include, but are not limited to:
- To calculate the mechanical advantage of a lever, you need to know the input force and the output force.
- The mechanical advantage is equal to the output force divided by the input force.
- The ideal mechanical advantage for a lever is equal to the distance from the input force to the fulcrum divided by the distance from the output force to the fulcrum.
- The ideal mechanical advantage assumes that the machine is 100% efficient.
- Acceptable responses may include, but are not limited to:
- To calculate the mechanical advantage of an inclined plane, you need to know the input force that is applied to the object moving up the inclined plane and the output force.
- To calculate an inclined plane’s ideal mechanical advantage divide the length of the inclined plane by its height.
- If the inclined plane’s length was longer, but the height remained the same, this would increase its mechanical advantage. Less input force would be needed to move the object up the inclined plane.
- If the inclined plane’s height was higher, but the length remained the same, this would decrease its mechanical advantage. More input force would be needed to move the object up the inclined plane.
- Acceptable responses may include, but are not limited to:
- Use a block and tackle system.
- A fixed pulley makes work easier by changing the direction of the input force. It does not reduce the input force needed to lift an object.
- A moveable pulley multiples the input force. However, the mechanical advantage of a single pulley can never be more than 2.
- A block and tackle system provides more rope sections to support the weight of the piano. This reduces the input force needed.
- A block and tackle system can have a mechanical advantage greater than 2.
