Use the definition of linear momentum from the previous question. Can we state the principle of conservation of linear momentum for a single particle?

Which of the two persons shown in figure (9-Q 1) is more likely to fait down? Which external force is responsible for his falling down?

Suppose we define a quantity ‘Linear Momentum’ as

linear momentum = mass x speed.

The linear momentum of a system of particles is the sum of linear momenta of the individual particles. Can we state a principle of conservation of linear momentum as “linear momentum of a system remains constant if no external force acts on it”?

To accelerate a car we ignite petrol in the engine of the car. Since only an external force can accelerate the center of mass, is it proper to say that “the force generated by the engine accelerates the car”?

A ball is moved on a horizontal table with some velocity. The ball stops after moving some distance. Which external force is responsible for the change in the momentum of the ball?