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A block pushed along the floor with velocity v0xslides a distance d after the pushing force is removed.

a. If the mass of the block is doubled but its initial velocity is not changed, what distance does the block slide before stopping?

b. If the initial velocity is doubled to2v0x but the mass is not changed, what distance does the block slide before stopping?

Short Answer

Expert verified

(a) The mass of an object has no bearing on the object's distance travelled. As a result, even if the mass of the object is doubled, the distance travelled remains constant.

(b) If the original velocity is twice, the object's distance travelled is four times that of the starting value.

Step by step solution

01

Introduction

Kinetic friction is the friction that occurs when an object moves in the opposite direction of its motion. When a pushing force is removed from an object, the body comes to a complete stop due to kinetic friction.

02

Explanation (a)

Apply kinematic equations to an object's motion.

vf2-vi2=2as

we seevfis velocity of the object, viis the starting velocity of the object, ais the acceleration of the object, and sis the distance travelled.

The object's frictional force acts in the opposite direction of its motion. The following is the kinetic frictional force acting on it:

fk=kmg

We see, kis the coefficient of kinetic friction, mis the mass of the object, and gis the acceleration due to gravity.

The net force acting on it is calculated using Newton's second rule of motion:

Fnet=-fk

ma=-kmg

a=-kg

Interchange and put 0 for vf,v0for vi,-kgfora,anddfors.

(0)2-v02=(2)-kgd

d=v022kg

The distance travelled by an object has nothing to do with its mass. As a result, the distance travelled remains constant even if the object's mass is doubled.

03

Explanation (b)

In this situation, the object's initial velocity is doubled while its mass remains unchanged. Consider the object's distance travelled in this scenario to bed'

Putting 0 for vf,2v0for vi,-kgfor a,andd'forsin the equation vf2-vi2=2a.

(0)2-2v02=(2)-kgd'

Equation rearrange for d'.

d'=4v022kg

=4v022kg

=4d

As a result, if the original velocity is double that of the initial number, the object has travelled four times as far.

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