Why is endurance training important to you?

Can somebody explain to me how newton's 3rd law relates to momentum? ~ap physics 1

Write the equation for momentum, first using symbols for the variables, then using words for the variables.

Determine the change in width a, height b, thickness t when a plate is subjected to the uniform distributed load and is made of material having modulus of elasticity e=230 gpa and poisson's ratio ν=1/3. given : a=400 mm and b= 300 mm also the uniformly distributed load in downward y direction of plate is 2 mn/m and in the positive x direction is 3 mn/m and t=20 mm