J.VEga
Guest

OK, Yurek, in practice it can arise some problems of construction or handling and for that is necessary to experiment. The jerk I believe that can be beared since the measurer will be progressive when absorbing the energy and to do as shock absorber. As far as scale of speeds, it is also relatively simple. Some formulas can clarify the subject: Let us call "r" to the radius of the pulley where it goes coiled the cord of retention and "R" to the one of the small disc that rotate over the great one which it have the measurement scale. "F" is the weight that suspended is able to make rotate the disc surpassing the friction, and that calculates experimentally for the apparatus once finished. "M" and "V" will be the mass and speed of the stone. Finally, "d" and "D" will be the displaced distance in the pulley and in the circumference of the smaller disc that rotater over the scale.
d/D = r/ R F x d = 1/2 ( M x V 2) V2 = (2FD)/M V = square root of (2FDr) / (MR) ( using correspondent unities)
So, each mark on the escale of D length (i.e.) will corresponde with an speed V, two marks with double speed, etc. ... is horrible to write formulas in a message...
Saludos Jesús
