A box with an initial speed of 8ms is moving up a ramp. The ramp has a kinetic friction coefficient of 32 and an incline of π4. How far along the ramp will the box go?

1 Answer
Nov 29, 2017

The distance is =2.77m

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=32

The acceleration due to gravity is g=9.8ms2

The incline of the ramp is θ=14π

a=9.8(32cos(14π)+sin(14π))

=11.57ms2

The negative sign indicates a deceleration

We apply the equation of motion

v2=u2+2as

u=8ms1

v=0

a=11.57ms2

s=v2u22a

=064211.57

=2.77m