[问答题]
A particle P starts from
rrvy s8d9m3v un gq+q2ho28p4j8tkdb0 xa n:w9l-s-oa point O and moves along a horizontal straight line. I
adsx:ktn-8 -ob0lw j9ts velocity$ v \mathrm{~ms}^{-1}$ after t seconds is given by
The following diagram shows the graph of v .
1. Find the initial velocity of particle P .
2. Find the acceleration of the particle in the first second.
3. How many times does the particle change direction in the first 8 seconds. Explain your answer.
4. Find the total distance travelled by the particle in the first 8 seconds.
