Answer:
When truck is at rest while student is under motion
Step-by-step explanation:
Since it is obvious that the mass of a truck is more than that of a student, we know that momentum is a product of mass and velocity
P=mv where m represent mass, v is velocity. When the student has more speed than that of truck, he exerts more momentum. The only way a student can exert more momentum is by having more speed while the truck is at rest. In such case, the momentum of truck will be zero while momentum of student will have a value