Bollnäs is a municipality in east central Sweden, in the county of Gävleborg. The municipality covers an area of 1827.1 km². Of the total population of 26735, 13238 are male, and 13497 are female. The population density of the community is 15 inhabitants per km².
... around inside the groove, the friction between the axis and the groove rims will accelerate or brake the spinning gyroscope, with a maximum effect when the axi ...