The number 'n' of cars produced at a certain factory in 1 day after 't' hours of operation is given by n(t)=100t-5t^2, 0< or equal t < or equal 10. if the cost 'c' (in dollars) of producing 'n' cars is c(n)=15,000+8000n, find the cost 'c' as a function of the time 't' of operation of the factory then interpret c(t) when t=5 hours as a new function.