a machine can make 56 parts in 4 hours. it can also make 70 parts in 5 hours. which rates could you use to write an equation of the form y= kx that represents the number of parts y the machine can make in x hours? A. 70 parts / 4 hours B. 70 parts / 5 hours C. 56 parts / 4 hours D. 56 parts / 5 hours

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 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)