The dot plot shows the time trials of an experiment. Each number on the dot plot represents the amount of time, in seconds, it took to complete a trial. How many time trials were recorded during the experiment? Enter the answer in the box. time trials A number line ranging from 15 to 25 with two dots over 15, three dots over 17, two dots over 19, two dots over 20, one dot over 21, four dots over 23, one dot over 24, and three dots over 25.

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)