DEFINITION of 'Human Development Index-HDI'. A tool developed by the United Nations to measure and rank countries' levels of social and economic development based on four criteria: Life expectancy at birth, mean years of schooling, expected years of schooling and gross national income per capita.EFINITION of 'Human Development Index-HDI'. A tool developed by the United Nations to measure and rank countries' levels of social and economic development based on four criteria: Life expectancy at birth, mean years of schooling, expected years of schooling and gross national income per capita.
A top and bottom gear rack are moving in the same direction but with different velocities (top rack 5 m/s and bottom rack 3 m/s). What is the angular velocity of the small attached gear B at the instant shown? Assume the top rack, bottom rack, and link AB remain horizontal.
The metre per second squared is the unit of acceleration in the International System of Units (SI). As a derived unit, it is composed from the SI base units of length, the metre, and time, the second. Its symbol is written in several forms as m/s 2, mÂ·s â2 or m s â2, or less commonly, as m/s/s. As acceleration, the unit is interpreted physically as change in velocity or speed per time interval, i.e. metre per second per second and is treated as a vector quantity.