A box with an initial speed of 7ms is moving up a ramp. The ramp has a kinetic friction coefficient of 73 and an incline of 5π12. How far along the ramp will the box go?

1 Answer
Jun 18, 2017

The distance is =1.06m

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=73

The incline of the ramp is θ=512π

a=9.8(73cos(512π)+sin(512π))

=23.08ms2

The negative sign indicates a deceleration

We apply the equation of motion

v2=u2+2as

u=7ms1

v=0

a=23.08ms2

s=v2u22a

=049223.08

=1.06m