Neil is going to make concrete. He is going to use 180 kg of cement 375 kg of sand 1080 kg of stone.

Cement, sand and stone are sold in bags, shown in the table.

Neil already has 15 bags of cement, 22 bags of sand and 18 bags of stone.

How much cement does Neil have?

Give your answer in kg.

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)