Question

Four identical lab carts each have a mass of 200 kg. Different masses are added to the carts and the velocities are measured. All carts move to the right. Which cart has the greatest momentum?

Answer 1

Momentum = mass × Velocity.

This means that the greater the mass the greater the momentum.

Or the greater the speed the greater the momentum.

Now given that the carts are identical but different masses are put on the carts it means that they have different momentum.

The cart with the largest mass has the highest momentum.

Answer 2

Four identical lab carts each have a mass of 200kg.
mass of each lab cart , m = 200kg

now, a/c to question, different masses are added to the carts and velocities are measured.
After that, mass of carts are ; $M_1,M_2,M_3\textbf{and},M_4$ and velocities are $V_1,V_2,V_3\textbf{and},V_4$ respectively.
so, momentum of first cart, $P_1=M_1V_1$
momentum of 2nd cart, $P_2=M_2V_2$
momentum of 3rd cart, $P_3=M_3V_3$
momentum of 4th cart, $P_4=M_4V_4$

here it clear that , momentum of cart will be greatest when product of mass and velocity of that cart will be greatest .