Question

Two objects of different masses have momentum of equal, non-zero magnitude. Which object has more kinetic energy?.

Answer 1

If they have the same momentum, then

m₁ v₁ = m₂ v₂

If m₁ > m₂, then we must have v₁ < v₂ to preserve the equality.

The object with the larger speed - the second object - thus has more kinetic energy.