[填空题]
A particle P moves along a stkj +djpq/en4 n0ft d;7raight lifw:a 8v 8ad7 fejej02one so that its velocity, $v \mathrm{~ms}^{-1}$ , after t seconds, is given by $v=\sin 3 t-2 \cos t-2$ , for $0 \leq t \leq 6$ . The initial displacement of P from a fixed point O is 5 metres.
1. Find the displacement of P from O after 6 seconds.
s=- m ; (two decimal places)
The following sketch shows the graph of v .
2. Find when the particle is first at rest.
t= s; (two decimal places)
3. Write down the number of times the particle changes direction.
hence time(s)
4. Find the acceleration of P after 2 seconds.
a(2)= ms$^{-2}$.(two decimal places)
5. Find the maximum speed of P .
