Question

A block of mass M is pulled along a horizontal frictionless surface by a tope of mass m . if a force p is applied st the free end of the roof , the force exerted by the rope on the block is [AIEEE 2003] ​

Answer 1

Explanation:

ANSWER

Consider the system as a whole

A block of mass M and a rope tied to it of mass m pulled by a force P,

The only external force

The system will accelerate due to the action of the force , all accelerating with same acceleration

Acceleration of the system =

Totalmass

Totalexternalforce

a =

m+M

P

Therefore acceleration of the block of mass M will also be a

Net force on it = mass x acceleration

This force is force of the rope on the block

Hence F =

m+M

PM

Answer 2

• Explanation:- Let acceleration of system ( rope + block ) be a along the direction of applied force . then ,
• a = P/M +m

Then draw FBD of block and root as shown in figure .

Where , T is the required parameter

• For block , T = ma
• ⟹T = Mp/M+m