gives the velocity at any point
, so you need only plug these values in:
Acceleration can be determined by differentiating the velocity function:
In order for any particle to reach the point
, we require that
be decreasing for some value of
. In other words,
must be negative for some
. This basically amounts to solving the inequality,
Note that the left hand side is negative when either
or
, but not both.
When
, in the first case you have
. But this isn't possible, since
(time) must always be growing in the positive direction.
Meanwhile, in the second case, you have
for all
, which means
can never be negative, which in turn means
must be increasing. Therefore it's not possible for any particle to reach a position of
for any
.