The law of the lever: how one apple can balance three

Lifting heavy objects using lighter ones

How can you use light ob­jects to lift heavy ones? Check it out with this video!

Safe­ty pre­cau­tions



  • 50cm wood beam;
  • thread;
  • hooks;
  • ap­ples;
  • small binder clips;
  • con­struc­tion tape mea­sure.

Step-by-step in­struc­tions

Use a tape mea­sure to de­ter­mine the cen­ter of a small wood beam. Fas­ten three binder clips to the beam: one fixed in the cen­ter, and two more mo­bile­ly on ei­ther side. Hang the stick on a hook by its cen­ter clip so that it can ro­tate freely. Your sim­ple lever is com­plete!

Process de­scrip­tion

A lever is a rigid body that can ro­tate around a cer­tain sup­port or sus­pen­sion point. In this case, our lever is a wood­en stick. An ap­ple sus­pend­ed at any point acts with its weight di­rect­ed ver­ti­cal­ly down­wards. Ap­ples sus­pend­ed on op­po­site sides of the sus­pen­sion point will strive to tilt the lever in op­po­site di­rec­tions. If the ap­ples are sus­pend­ed at equal dis­tances from the cen­ter, the lever will tilt to the side with the heav­ier weight. In chang­ing the sup­port point of a load, one can achieve a bal­anced lever. One ap­ple can thus bal­ance three!