Lesson 3
Part 2

Marvelous Machines: Making Work Easier

Using Simple Machines (2) / Grade 5 / Andover, MA

The EIE Curriculum

EiE - Marvelous Machines: Making Work Easier, L3 Part 2

Students use simple machines and spring scales to determine how much force is needed to move a standard load and think about the ergonomics of using each machine.

Reflection Questions

What evidence do you see that Tim’s students are beginning to develop an understanding that all simple machines have advantages and disadvantages?

Tim’s students talk about both ergonomic advantages to some of the machines, and force advantages. They also talk about the advantages of some of the simple machines that do not provide a force advantage.

  • Tim asks students to compare the three lever positions they tested, both in terms of ergonomics and force required. Even though the class decides there’s no force or ergonomic advantage to using position C, they note that it does create a greater distance between the fulcrum and the load, which allows them to swing the load in a wider arc. (5:41)
  • When discussing the pulleys, students note that the benefit of the single pulley is that they get to just pull down, though the force required is not changed. (7:13)