Question

Two similar planes of mass m each having failed engines are being pulled by a stronger plane in air. At t = 0, they are travelling at uniform speed producing tension T_Ain rope A. The stronger plane then accelerates with acceleration a. Tension in rope B just after the beginning of acceleration is

• A. T_A
• B. T_A– ma
• C. 2T_A+ma
• D. T_A/2+ ma

Answer 1

Answer: (D)

T_A/2+ ma

Answer 2

Before accelerating, tension at rope B is T = $\frac { 1 } { 2 }$ × tension at rope A= $\frac { \mathrm { T } _ { \mathrm { A } } } { 2 }$

Just after acceleration, total tension in rope B is given by T_total

= $\frac { \mathrm { T } _ { \mathrm { A } } } { 2 }$ + ma.