Question

A thin string is wrapped several times around a cylinder kept on a rough horizontal surface. A boy
standing at a distance from the cylinder draws the string towards him as shown in figure. The cylinder
rolls without slipping. The length of the string passed through the hand of the boy while the cylinder
reaches his hand
1. L
2.2L
3.3L
4.4L

(anwer if u know..otherwise just shut up)​

Answer 1

Explanation:

A thin string is wrapped several times around a cylinder kept on a rough horizontal surface. A boy

standing at a distance from the cylinder draws the string towards him as shown in figure. The cylinder

rolls without slipping. The length of the string passed through the hand of the boy while the cylinder

reaches his hand

1. L

2.2L

3.3L

4.4L

(anwer if u know..otherwise

Answer 2

Answer:

let we assume the cylinder has the radius r , you have assume it dont worry about it as the cylinder is hollow just take the radius be r and now we have to consider the angular speed of the cylinder as any one should understand that cylinder has angular speed let that be A since by formulla we have Cr=A where c is linear speed speed of cylinder . now the speed of string on the cylinder is at some point be A + Cp = 2A ( as p is the distance of any point from centre there p=r and therefore Cp/Cr = A as derived first) there fore in time t = L/A cylinder reaches the boy the string will cover the distance 2At = 2L