Making a simple pendulum clock puts the physics of periodic motion directly in your student’s hands. The lab sheet walks grades 4 through 7 through six assembly steps, from attaching a wooden dowel vertically to a base board and threading string through an eye screw, to mounting a printable clock face and cutting a cardboard pointer. Students begin with a pendulum length of 12 to 16 inches from pivot to bob, swing 20 times, and record the time per swing across three separate trials in the built-in data table.

The challenge question at the bottom raises the stakes: can your homeschooler adjust the pendulum until 20 swings land as close to 20 seconds as possible, hitting exactly one second per swing? That single goal makes this lab fit naturally into a physics unit study on force and motion, or as a standalone investigation into how mechanical clocks work. By the time your student answers all three think-and-explain questions, they can articulate why longer pendulums swing slower and why that consistency made pendulum clocks the world’s most accurate timekeepers for two centuries.