A box with an initial speed of 8ms is moving up a ramp. The ramp has a kinetic friction coefficient of 43 and an incline of π6. How far along the ramp will the box go?

1 Answer
Jul 11, 2017

The distance is =1.97m

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

ma=μkgcosθmgsinθ

a=g(μkcosθ+sinθ)

The coefficient of kinetic friction is μk=43

The incline of the ramp is θ=16π

a=9.8(43cos(16π)+sin(16π))

=16.22ms2

The negative sign indicates a deceleration

We apply the equation of motion

v2=u2+2as

u=8ms1

v=0

a=16.22ms2

s=v2u22a

=064216.02

=1.97m

NOTE : The coefficient of friction μk>1 means that the frictional force is greater than the normal force.