抄録
We have succeeded in constructing a frictionless demonstration equipment for mechanics by utilizing very simple tools, such as fine spherical plastic beads (0.3mm in diameter), a glass Petri dish (40-80mm in diameter), an aluminum disk (51mm in diameter and 5mm thick), and a large box consisting of glass plate of 8mm thick (box size is 1000×100×50mm). The fine plastic beads work as ball-bearings to significantly reduce the friction between the object and the surface. The coefficient of static friction has been estimated to be about 0.003. We have demonstrated some basic laws of mechanics by using the frictionless surface. They are the law of inertia and the conservation of momentum upon collision of two objects. Additionally, we have also demonstrated the motion of constant acceleration by tilting the frictionless surface into an inclined slope. It was confirmed that quantitative measurements are also possible using a stroboscopic photograph technique, exhibiting a good correlation between the experimental observation and the theoretical calculation.
