Question

Please don't answer the question by submitting a picture of solution, text only. For college physics discussion post. Be sure to have examples.

Respond to the following:

• Explain conservation of momentum and give examples in daily life.
• In your own words, explain impulse and give examples in daily life.
• In your own words, center of mass and give examples in daily life.

Answer 1

(1)

The momentum of an isolated system of two or more than two interacting bodies remains constant.”Momentum of a system depends on its mass and velocity.A system is a group of bodies within certain boundaries .An isolated system is a group of interacting bodies on which no external force is acting.It is expressed mathematically as:

Above formula states that momentum of two striking bodies before and after collision remains same.

Conservation of momentum examples in real life

• Consider the example of air-filled balloon as described under the third law of motion.In this case, balloon and the air inside it form a system.Before releasing the balloon,the system was at rest and hence the initial momentum of the system was zero.As soon as the balloon is set free,air escapes out of it possesses momentum.To conserve momentum, the balloon moves in a direction opposite to that of air rushing out.

(2)

Impulse is any force which acts for a very small amount of time.

Most famous and commonly quoted - Batsman hitting the ball while playing cricket. The bat is in contact with the ball for very less time but changes its course quite significantly.

(3)  

The center of mass is a position defined relative to an object or system of objects. It is the average position of all the parts of the system, weighted according to their masses.

For simple rigid objects with uniform density, the center of mass is located at the centroid.

For example, the center of mass of a uniform disc shape would be at its center