From the information given, the mass of the moving body, which in this case is a person, is 72 kg and the momentum 700 kg m/s.
we use the formula p = m × v.
Where p is momentum, m is the mass and v is the velocity.
We need v so we rewrite the equation thus: v = p/m
In our case p = 700 and m = 72
v = p/m → v = 700/ 72 → v = 9.72
Therefore the person is travelling at 9.72 m/s