[填空题]
An object is moving along a straight line such that its velocitymi, k-pimf d;/sln ni5 3mq/b1.smkd1, v, e4 ixjfd 1n)7tf3/if g$\mathrm{~ms}^{-1}$ , is given by $v(t)=5 t e^{-1.2 t}$ , for $t \geq 0 $.(two decimal places)
1. On the grid below, sketch the graph of v , for $0 \leq t \leq 3$ .
2. Find the distance travelled by the object in the first 3 seconds.
d= m
3. Find the velocity of the object when its acceleration is zero.
v(0.833)= ms$^{-1}$
