Question

Two particles A and B start moving due to their mutual interaction only. If at any time 't', and $\overrightarrow { \mathrm { a } } _ { \mathrm { B } }$ are their respective accelerations, and $\overrightarrow { \mathrm { v } } _ { \mathrm { B } }$ are their respective velocities and upto that time W_A and W_B are the work done on A and B respectively by the mutual force, m_A and m_B are their masses respectively, then which of the following is always correct -

• A.
• B. $\mathrm { m } _ { \mathrm { A } } \overrightarrow { \mathrm { v } } _ { \mathrm { A } } + \mathrm { m } _ { \mathrm { B } } \overrightarrow { \mathrm { v } } _ { \mathrm { B } } = 0$
• C. W_A + W_B = 0
• D.

Answer 1

Answer: (B)

$\mathrm { m } _ { \mathrm { A } } \overrightarrow { \mathrm { v } } _ { \mathrm { A } } + \mathrm { m } _ { \mathrm { B } } \overrightarrow { \mathrm { v } } _ { \mathrm { B } } = 0$

Answer 2

Since $\sum \overrightarrow { \mathrm { F } } _ { \mathrm { ext } } = \overrightarrow { 0 }$

\f0 Moment of system will remain conserved, equal to zero.