Question

If no external force acts on a system

• A. Total Momentum of the system is conserved
• B. Position of centre of mass is not constant
• C. Acceleration of centre of mass remains zero and constant
• D. All of the above

Answer 1

The correct option is A Total Momentum of the system is conserved

From the Newton's second law,

$F=\frac{dp}{dt}$

If no external force acts on a system, $F=0N$

$\frac{dp}{dt}=0$

$dp=0$

By integrating,

$\int dp=constant$

$p=constant$

The total momentum of the system is conserved.

The correct option is A.