Answer
The bicycle and the car have the same momentum when the bicycle is moving at a speed of 75 m/s
Work Step by Step
In general, the momentum is $p = mv$.
We can equate the momentum of the bicycle and the momentum of the car to find the required speed $v$ of the bicycle.
$p_{cyclist} = p_{car}$
$(100~kg)~v = (1500~kg)(5.0~m/s)$
$v = \frac{(1500~kg)(5.0~m/s)}{100~kg}$
$v = 75~m/s$
The bicycle and the car have the same momentum when the bicycle is moving at a speed of 75 m/s.