Question

A dog of mass 10 kg is standing on a flat 10 m long boat so that is 20 meters from the shore. it walks 8 m on the boat towards the shore and then stops. the mass of the boat is 40 kg and friction between the boat and th water surface is negligible. how far is the dog from the shore now?

Answer 1

hey friend here is your answer you are looking for:-

no.of metre=20
dog passed metre=8
=20-8=12

therefore -12 m are left to pass the shore.

hope it helps please Mark me as a brinialiest.

Answer 2

Hey.

Here is your answer.


let the x1 is the distance of center of mass of boat from the shore,and Xc.m is the distance of  center of mass of the system from the shore

Xc.m =(10*20 +40*x1)/(40+10)

          =4 +(4/5)  x1

now let boat move x distance away from the shore when dog move 8m towards the shore

so new distance of boat from shore=x1 +x

new distance of dog from shore=20- 8 +x=12+x

now

 Xc.m ={10*(8+x) +40*(x1+x)}/(40+10)

          =(80+50x +40x1)/50

          =8/5 +x +4/5x1

 

equate both Xc.m

8/5 +x +4/5x1 =4+(4/5)  x1

 x=4-8/5

  =12/5

so distance =8+12/5

                 =52/5

Thanks.