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
I personally think that it’s C.
(i’m sorry if it’s wrong)
Answer:
Visible wavelengths range from 0.0007 milimeters for red light, through orange, yellow, green, and blue, to 0.0004 milimeters for violet light.
Ultraviolet is shorter wavelengths than violet.
Hope This Helps.
Step 1 - Since 3.3mm^3 = 0.0033cm^3, convert that to 3.3x10^-3 cm^3.
Step 2 - Since 1cm^3 = 1x10^-6 m^3, times 3.3 by that. (3.3 x 1 x 10^-6) = 0.0000033
Step 3 - 0.0000033 = 3.3 x 10 ^-6 m^3, which is your answer choice A.
*if you do not understand, message me and I will go through it more thoroughly!!*
Have a great day!! :)