Answer: The momentum of the child and milk together is 58.125 kg.m/s
Explanation:
Momentum is defined as the product of object's mass and velocity.
Mathematically,
where, p = momentum
m = mass of the object
v = velocity of the object
In the given question, we are given that a child of mass 21.0 kg is carrying a gallon of milk having mass 2.25 kg and running with a velocity of 2.5 m/s. Hence, the momentum by both milk and child will be:
....(1)
Given:
Putting values in equation 1, we get:
Hence, the momentum of the child and milk together is 58.125 kg.m/s