A 66.1-kg person, running horizontally with a velocity of +2.23 m/s, jumps onto a 14.1-kg sled that is initially at rest. (a) Ignoring the effects of friction during the collision, find the velocity of the sled and person as they move away. (b) The sled and person coast 30.0 m on level snow before coming to rest. What is the coefficient of kinetic friction between the sled and the snow? (a) Number i (b) Number i Units Units

how it become 0.829? if i multiply the numbers it will give me 5096?

Not complicated answer, and not too long explanation

For this question, can you explain how we get the integral from dFz to Fz. Can you also explain how im supposed to know which proportion to use? In some similar question we use proportions such as dQ/dl and in other question we use dz/d theta. How do i know which proportion to use for the question?