所谓货币流通速度V是指实际GNP与实际货币持有量的比率，V=Y／（M／P)。请利用等式（14－4)推导货币流通速度的表达

所谓货币流通速度V是指实际GNP与实际货币持有量的比率，V=Y/(M/P)。请利用等式(14-4)推导货币流通速度的表达式，并解释货币流通速度是如何随R和Y的变化而变动的。(提示：产出变化对v的影响取决于相对于实际产出的货币总需求弹性，经济学家认为该弹性小于1。)货币流通速度与汇率之间存在什么联系？

The velocity of money，V，is defined as the ratio of real GNP to real money holdings，V=Y/(M/P)in this chapter's notation．Use equation(14-4)to derive an expression for velocity and explain how velocity varies with changes in R and in Y．(Hint：The effect of output changes on V depends on the elasticity of aggregate money demand with respect to real output，which economists believe to be less than unity．)What is the relationship between velocity and the exchange rate？