Question

A rope of length 10m and linear density 0.5kg/
m is lying length wise on a smooth horizontal
floor. It is pulled by a force of 25 N. The tension
in the rope at a point 6m away from the point of
application is
A) 20 N
B) 15 N
C) 10 N
D) 5N​

Answer 1

Length slope =10m

Density =0.5kg/m

Given the floor is smooth

T=25N

(Ref image)

FBDs of the two parts

Let total mars of rope be m.

The left part has a mars 0.6m and right part  

mars 0.4m as rope is uniform.

The rope moves as a single piece.

So acceleration of both parts have to be same

T−T  

1

=(0.6m) a from (1)

T  

1

=0.4ma from (2) of ma=  

0.4

T

​  

 

T−T  

1

=0.6×T  

1

0.4

T=2.5T  

1

 

T  

1

=2T

5

Putting T=25N

            T  

1

=10N