Your mining company is considering an expansion of operations into iron ore. your engineers surveyed a particular piece of land three weeks ago (the survey cost $45,000) and concluded the following:

you can extract 2,500 tons of iron ore per year.
there are 10,000 tons of iron ore underneath this land. once all the ore has 
been extracted, the project will cease to produce any revenues.
the price of ore will remain constant for the next 4 years. currently ore sells 
for $120 per ton.
the operating cost to extract the ore will be $80 per ton for the next 4 years.
we can invest in the equipment for this project right now for $100,000.
the equipment will be fully depreciated over a period of four years using the 
straight-line method.
at the end of year 4, we can sell the equipment involved in the project for 
$25,000
the expansion requires additional working capital (nwc) of $15,000 from 
the start (at time t=0) until the end of year 4. at time t=4, working capital 
decreases to $0.
the tax rate is assumed to be 35%. your cost of capital is 11%.
provide the free cash flow for each year of this project (times t=0 through t=4) and compute the project’s npv.

t = 0 cash flow:

t = 1 cash flow:

t = 2 cash flow:

t = 3 cash flow:

t = 4 cash flow:

project npv: