Please review video of the Motor Horizontal Brake Performance Tester as below link:
Load the toy a suitable static strength load. Measuring the force required to pull the toy on a horizontal plane covered with a surface of abrasive paper (aluminium oxide P60) at a constant speed of (2 ± 0,2) m/s. The motor shall be considered to supply sufficient braking if:
FT1 ≥ (M + 25) x 1.7 or FT2 ≥ (M + 50) x 1.7
where
FT1 is the maximum pull force in Newtons for a toy intended for children under 36 months;
FT2 is the maximum pull force in Newtons for a toy intended for children of 36 months and over;
M is the mass of the toy in kilograms.