A box with an initial speed of 8ms is moving up a ramp. The ramp has a kinetic friction coefficient of 87 and an incline of π4. How far along the ramp will the box go?

1 Answer
Jun 3, 2017

The distance is =2.15m

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)

a=9.8(87cos(14π)+sin(14π))

=14.85ms2

The negative sign indicates a deceleration

We apply the equation of motion

v2=u2+2as

u=8ms1

v=0

a=14.85ms2

s=v2u22a

=064214.85

=2.15m