A truck and a car are going with the same velocity
Clearly momentum of the truck is greater than the momentum of the car
Now brakes are applied at the same time.
Implies both the truck and the car are decelerated or retarded at the same time. The deceleration produced in each is given by Newton's second Law
We know from kinematics that final velocity
Inserting value of
Solving for distance we get
And as per initial conditions
From this relationship we can say that for the same retarding force
However, we need to specify specific values for the respective masses and braking powers to assess the situation.