# If the coeffiencent of friction is F/R, what do you substitute in to find F and R?

work done by the applied force
work = force x distance = ? in joules

gain in potential energy of the block
mass x change in height

(work done by force - gain in potential energy) / (MG cos angle)

the mass of my block was 0.3389kg
mass x 9.81 = 3.324609

distance of 214.60 cm

veritcal height og 0.6425m

## The Attempt at a Solution

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tiny-tim
Homework Helper
welcome to pf!

hi emscare! welcome to pf!

there seems to be something missing from the question … perhaps an initial and final velocity?

what exactly is the whole question?​

basically im trying to find the coefficient of fricition between two wooden surfaces but im struggeling with the equation :-)

tiny-tim
Homework Helper
show us your full calculations, and then we'll see what went wrong, and we'll know how to help!

co-efficient of friction (µ) = F/R

F is work done by the applied force - gain in potential energy
R is mass x gravity x cos (angle of incline)

I calculated work done by the applied force by: force x distance where the force = mass x 9.81

I calculated gain in potential energy by mass x height of ramp

*both above are in joules

my answer should be around 1.2

what am i missing :? this is way above anything iv been taught and the formula isnt explained well on google :(

tiny-tim
Homework Helper
what am i missing :?
erm

you haven't told us what the full question is,

and you haven't shown any of your actual calculations!

working attached as picture

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the full question is what is the coeffiecent of friction between the two surfaces

tiny-tim
Homework Helper
i don't understand

Post Question: If the coeffiencent of friction is F/R, what do you substitute in to find F and R?

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has anybody come accross this formular before?

is there another way to calculate the gain in potential energy

how do i delete this?