The linear momentum of a runner in a 100m dash is 750kg m/s. If the runners speed is 10m/s, What is his mass

The mass of the runner is 75 kg

Explanation:

Recall that the linear momentum is defined as the product of the mass of the object in motion times its velocity:  P = m * v

Therefore, for our case we have;

750 kg m/s = m * 10 m/s

solving for the mass (m) we get:

m = 750/10 kg =75 kg

your answer would be fusion