In conduction, the thermal energy of a particle is transferred to other particles throughout the solid. The particles with more energy are transferred to those with less.
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
To convert the given value to the desired one, use the proper unit conversions and dimensional analysis. Use the following conversion for the first set.
1 g = 100 cg
1 L = 1000 mL
Using the concept presented above,
V = (59800 cg/L)(1 g/100 cg)1 L/1000 mL)
V = 0.598 g/mL
The answer is d hope this helps