A box with a mass of 4kg and initial speed of 3ms is moving up a ramp. The ramp has a kinetic friction coefficient of 2 and an incline of π12. How far along the ramp will the box go?

1 Answer
Jan 6, 2018

The distance is =0.38m

Explanation:

Resolving in 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=2

The acceleration due to gravity is g=9.8ms2

The incline of the ramp is θ=112π

a=9.8(2cos(112π)+sin(112π))

=11.99ms2

The negative sign indicates a deceleration

We apply the equation of motion

v2=u2+2as

u=3ms1

v=0

a=9.3ms2

s=v2u22a

=09211.99

=0.38m