Suppose a rock is thrown off of a bridge into the river 120 feet below. The height, h, in feet of the rock above the river is given by h = −16t2 + 84t + 120, where t is the time in seconds. How long does it take the rock to splash into the river below?

2. using calculations based on a perpetual inventory system, determine the inventory balance altira would report in its august 31, 2021, balance sheet and the cost of goods sold it would report in its august 2021 income statement using the average cost method. (round "average cost per unit" to 2 decimal places.)