Suppose you push a hockey puck of mass m across frictionless ice for 1.0 s, starting from rest, giving the puck speed v after traveling distance d. If you repeat the experiment with a puck of mass 2m, pushing with the same force, a. How long will you have to push for the puck to reach the same speed v?

b. How long will you have to push for the puck to travel the same distance d?

Short Answer

Expert verified

(a) Puck Btakes twice as long as puck mass to reach the same speed A.

(b) As a result, the puck takes a long time. Bto travel the distance dis 2times the amount of time it takes for a puck to go a certain distance A.

Step by step solution

01

Introduction

The kinematic equation for motion along a straight line is as follows:x-axis ,

v1x=v0x+axt

We v1xis the highest possible velocityv0xis the beginning speed,axis the acceleration and tis the time interval.

The following is the kinematics expression for distance travelled:

x1-x0=+v01t+12axt2

By all above x1is the final position and x0initial position of the puck.

02

Explanation (a)

For mass puck A, the formulation of Newton's second rule of motion(m)is as follows,

Fx=max

Rearrange the phrase of Newton's second law of motion to find the value of acceleration.ax,

ax=Fxm

The time it takes for the puck to reach the specified velocityvis calculated as follows,

Calculation of the time required by mass puck Amto reach the speed vis as follows,

Puttingvfor v1x,0m/sfor v0x,Fxmfor axand tmpxfor tin the kinematics equation,

v=0m/s+Fxmtm,puk

tm,puck&=mvFx

For mass puck B, the formulation of Newton's second equation of motion(2m)is as follows,

Fx=2max

To calculate the value of acceleration, rearrange the phrase of Newton's second law of motionax,

ax=Fx2m

The amount of time it takes for the puck to attain the desired speed vis calculated as follows,

Calculation of the time required by mass puck B2mto reach the speed vis as follows,

Puttingvforv1x,0m/sfor v0x,Fx2mfor axand t2m puckfor tin the kinematics equation,

v=0m/s+Fx2mt2mpudk

t2mpokk=2mvFx

=2mvFx

Putting tm.puckfor mvFxfrom the expression of time of puck A of mass m,

t2m,pack=2tm,pok

As a result, puck B takes twice as long to reach the same speed as puck massA.

03

Explanation (b)

Calculate the amount of time puckA of mass takes to travelmis as follows,

Puttingdfor x1-x0,0m/sfor v0x,Fxmfor axandtmpatfor t in the kinematics equation,

d=0+12Fxmtm,puok2

tmpuak=2mdFx

Calculation of time taken by puckBof

Calculation of the time required by mass puck Bmis as follows, Puttingvfor v1x,0m/sfor v0x,Fx2mfor axand t2m, pusfor tin the kinematics equation,

d=0+12Fx2mt2m,puck2

t2m,puck=4mdFx

=22mdFx

Putting tm,puckfor 2mdFxfrom the mass puck A statement of time m,

t2m,puck=2tm,puck

As a result, the puck spends more time on the iceB to travel a considerable distance dis 2times and time taken by the puck's mass A.

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