A box with an initial speed of 3ms is moving up a ramp. The ramp has a kinetic friction coefficient of 13 and an incline of π3. How far along the ramp will the box go?

2 Answers
Mar 17, 2018

Here,as the tendency of the block is to move upwards,hence the frictional force will act along with the component of its weight along the plane to decelerate its motion.

So,net force acting downwards along the plane is (mgsin(π3)+μmgcos(π3))

So,net deceleration will be (g32+13g(12))=10.12ms2

So,if it moves upward along the plane by xm then we can write,

02=322×10.12×x (using, v2=u22as and after reaching maximum distance,velocity will become zero)

So, x=0.45m

Mar 17, 2018

The distance is =0.44m

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 of Motion

F=ma

Where a is the acceleration of the box

So

ma=μkgcosθmgsinθ

a=g(μkcosθ+sinθ)

The coefficient of kinetic friction is μk=13

The acceleration due to gravity is g=9.8ms2

The incline of the ramp is θ=13π

The acceleration is a=9.8(13cos(13π)+sin(13π))

=10.12ms2

The negative sign indicates a deceleration

Apply the equation of motion

v2=u2+2as

The initial velocity is u=3ms1

The final velocity is v=0

The acceleration is a=10.12ms2

The distance is s=v2u22a

=09210.12

=0.44m