Question

Physics !

In a laboratory experiment on friction, a 135-N block resting on a rough horizontal table is pulled by a horizontal wire. The pull gradually increases until the block begins to move and continues to increase thereafter.

Find the coefficients of static and kinetic friction between the block and the table

Answer 1

The graph should look like a straight line increasing steadily to the right until the block begins to move, then the friction force will drop straight down some amount and be flat throughout the rest of the graph. The flat part is where kinetic friction has kicked in, so
kinetic µ = Ff / Fn = Ff / mg
where Ff is the force of friction.

static µ = Ffmax / mg
where max friction force on the graph occured just before the block started moving.

Answer 2

i saw that in yaho answers aswell, but i need explanation, first what would be my net force?

Answer 3

lol

Answer 4

" Since the normal force will have doubled, the max friction force will double as well, to 150N. Then it will drop, as before, but to a doubled value -- 100N, where it will remain constant. So the graph will have the same shape, just expanded up and to the right, if you will. The coefficients of static and kinetic friction should be unchanged since the same two surfaces are in contact"

Answer 5

Sorry I'm just trying to help out the best i can bc i dont know how to solve it and everything helps.

Answer 6

appreciate it tbh xD

Answer 7

the magnitude of the net force, is given by:
magnitude of total pulling force minus magnitude of friction force:
\[{F_{NET}} = {F_{TOTAL}} - {F_{FRICTION}}\]

Answer 8

okay, looking at the graph i have, im starting to actually understand it, the question i posted was incomplete because i already knew how to read the graph, so i though it would be unnecessary