JEE Main Form Correction 2025 - Date (Out), Procedure, Guidelines, Fee

Motion Of Blocks When Connected With String - Practice Questions & MCQ

Edited By admin | Updated on Sep 18, 2023 18:34 AM | #JEE Main

Quick Facts

  • Motion of blocks when connected with string is considered one of the most asked concept.

  • 3 Questions around this concept.

Solve by difficulty

Three identical blocks of masses 2kg each, are kept on smooth surface. The system is drawn by applying forces of 15N and 3N as shown in the figure. Determine the Tension T1  (in N) in one string as shown in the figure.

Concepts Covered - 1

Motion of blocks when connected with string

 

  1. Two blocks connected with a string on smooth horizontal surface

Let accelereration of the blocks be 'a', and Tension in the string be T.

F.B.D of both blocks combined-

\\ From\ F_{net}=M_{sys}a\\ F=(m_{1}+m_{2})a\\ \Rightarrow a=\frac{F}{m_{1}+m_{2}}\ ...(1)

F.B.D of block of mass m1-

\\ From\ F_{net}=M_{sys}a\\ T=m_{1}a\\ From\ equation (1)\\ \Rightarrow T=\frac{m_{1}F}{m_{1}+m_{2}} \ ...(2)

  1. Three blocks connected with a string on smooth horizontal surface

Let accelereration of the blocks be 'a', tension in the string between m1 and m2 be T1, and tension between m2 and m3 be T2.

F.B.D of all the blocks combined-

\\ From\ F_{net}=M_{sys}a\\ F=(m_{1}+m_{2}+m_{3})a\\ \Rightarrow a=\frac{F}{m_{1}+m_{2}+m_{3}} \ ...(1)

F.B.D of block m1-

\\ From\ F_{net}=M_{sys}a\\ T_{1}=m_{1}a\\ From\ equation\ (1)-\\ \Rightarrow T_{1}=\frac{m_{1}F}{m_{1}+m_{2}+m_{3}}\ ...(2)

F.B.D of m3-

\\ From\ F_{net}=M_{sys}a\\ F-T_{2}=m_{3}a\\ \Rightarrow T_{2}=\frac{(m_{1}+m_{2})F}{m_{1}+m_{2}+m_{3}}\ ...(3)

 

Study it with Videos

Motion of blocks when connected with string

"Stay in the loop. Receive exam news, study resources, and expert advice!"

Get Answer to all your questions

Back to top