Answer to Question #97817 in Mechanics | Relativity for C

Question

I don’t understand what momentum,impulse and conservation of mechanical energy.May you please explain it in the simplest terms with an easy example please?Thanks

Answer 1

Momentum is a product of mass and a material object and its acceleration.

The value is vector, that is, it has a direction. All bodies that move in space will have a certain momentum value. As an example, consider a game of billiards: after hitting a cue ball on a billiard ball, kinetic energy is transmitted to it, the ball acquires a speed from which one can calculate the acceleration and calculate its momentum.

Impulse of force is a change in momentum, which is caused by the influence of this force.

For a finite period of time, this value is equal to a certain integral of the elementary momentum of the force, where the integration limits are the moments of the beginning and end of the period of time the force acts. Obviously, the impulse will directly depend on the time of the force. For example, to minimize this parameter, seat belts are used in cars.

Mechanical energy in mechanics is the sum of the potential and kinetic energy in a separate concrete system. The principle of conservation of mechanical energy states that the total mechanical energy in the system remains constant, while the only acting forces on this system are exclusively conservative forces.

For example, a waterfall. So, while the water flows horizontally (we believe that this is a river), it has a certain kinetic energy. When it begins to move vertically (directly the waterfall itself), the water "acquires" energy. potential, which will be equal to kinetic energy (that is, immediately before the moment of fall).