* Units: We need to be consistent with units. "5 sec" is a unit of time, not velocity. Velocity is usually measured in meters per second (m/s). Let's assume the ball's velocity is 5 m/s.

* Mass of the Second Ball: To calculate the momentum of the second ball, we need to know its mass.

Here's how to calculate momentum:

Momentum (p) = Mass (m) × Velocity (v)

Ball 1 (Moving Ball):

* Mass (m₁) = 1 kg

* Velocity (v₁) = 5 m/s

* Momentum (p₁) = m₁ × v₁ = 1 kg × 5 m/s = 5 kg m/s

Ball 2 (Stationary Ball):

* Velocity (v₂) = 0 m/s (since it's stationary)

* Let's assume the mass of the second ball is m₂.

* Momentum (p₂) = m₂ × v₂ = m₂ × 0 m/s = 0 kg m/s

Important Note: The momentum of the stationary ball is always zero because its velocity is zero.

Let me know if you have the mass of the second ball, and I can calculate its momentum.