Why can the fed control the real interest rate in the short run but not in the long run?

Cash flows during the first year of operations for the harman-kardon consulting company were as follows: cash collected from customers, $385,000; cash paid for rent, $49,000; cash paid to employees for services rendered during the year, $129,000; cash paid for utilities, $59,000. in addition, you determine that customers owed the company $69,000 at the end of the year and no bad debts were anticipated. also, the company owed the gas and electric company $2,900 at year-end, and the rent payment was for a two-year period.