Question

Use Newton’s laws to calculate the force of friction. Remember that the shoe is moving at constant velocity. How must the applied force compare to the force of kinetic friction?
From the force of friction, calculate the coefficient of kinetic friction for each trial.
Plot the force of friction vs. the weight for each trial of each shoe. You will have two lines on the same graph, one for each shoe. Calculate the slope of each line and write it down.

Someone please help this is due today and i have no idea how to do it.

Answer 1

here is the table

Answer 2

Welcome to OS! Sorry I haven't quite done friction yet (actually supposed to start it next week). We can try to learn this together. Do you know how to calculate the frictional force? After that the next step would be to plot the graph.

Answer 3

no i dont really understand how to calculate frictional force

Answer 4

i looked up the equation for it and got Ffrict=the mew symbol*Fnorm

Answer 5

Ok, that's what I'm getting, too. Since the acceleration is 0 (constant velocity) we know that:
\[\Sigma F = ma\]
\[F_{app} - F_{k} = ma\]
And since ma = 0 (cause anything times 0 is 0)
\[F_{app} = F_{k}\]
Does that sound right?

Answer 6

yes sort of

Answer 7

so how would we set up fapp=fk

Answer 8

here is the lab table again only that i converted the weight into kilograms and grams

Answer 9

Sorry it took me so long. Since the applied force equals the kinetic frictional force, you can put that in the table and graph it, I think? It wanted you to graph frictional force versus weight.

Answer 10

wait im confused what is the kinetic frictional then i know what my applied force is but not the kinetic

Answer 11

as @SapphireMoon said, \(F_f = F _a\) because the shoe has constant velocity


weight and friction force are related as \(F_f = \mu W\)

so \(\dfrac{F_f}{W} = \mu \)

so the slope of ypur lines will be \(\mu\), ie the coefficient of kinetic (moving or sliding) friction

the sports shoes should have greater friction