[填空题]
The graphs of displacement, velocity 4,ohhbtjvn8w 1x(urd5p3 1xwand acceleration of a roller coaster in a t ujo dpn4381xwh,wv(r 5ht1 bxdd-l/ys)y(p 03 y6ugvbn i l8gheme park are shown in thp )8v/gyd(gs 6dly0yn li ub3-e following diagram.
1. Complete the following table by noting which graph A, B or C corresponds to each function.
When function is displacesment ;the graph is
When function is acceleration ;the graph is .
2. Write down the value of t when the velocity is greatest.
t= .