A box with an initial speed of 9ms is moving up a ramp. The ramp has a kinetic friction coefficient of 75 and an incline of 5π12. How far along the ramp will the box go?

1 Answer
Jun 17, 2017

The distance is =3.11m

Explanation:

Taking the direction up and parallel to the plane as positive +

The coefficient of kinetic friction is μk=FrN

Then the net force on the object is

F=FrWsinθ

=Frmgsinθ

=μkNmgsinθ

=mμkgcosθmgsinθ

According to Newton's Second Law

F=ma

Where a is the acceleration

So

ma=μkgcosθmgsinθ

a=g(μkcosθ+sinθ)

The coefficient of kinetic friction is μk=75

The incline of the ramp is θ=512π

a=9.8(75cos(512π)+sin(512π))

=13.02ms2

The negative sign indicates a deceleration

We apply the equation of motion

v2=u2+2as

u=9ms1

v=0

a=10.54ms2

s=v2u22a

=081213.02

3.11m