2.5 Impulse, Work, Energy, and Momentum

What is the principle of linear momentum ?

What is an impulse ?

When 2 bodies interact together for a very short period of time, we can’t calculate in details the force at each instant, so we use the impulsion

What is the law of conservation of momentum ?

A momentum can be transferred from one body to another but,the sum of the individual momentums of a system remains constant

What is the formula for mechanical work ?

Its unit is N.m so J

What is the formula for the work done by gravity ?

What is the formula for the acceleration work against the inertia force ?

What is the formula for the work done by a spring ?

What is the kinetic energy formula ?

What is the potential energy formula ?

It is given by gravitational (potential) energy from the work done by gravity

What is the gravitational energy formula ?

What is the elastic (potential) energy formula from the work done by a spring ?

What is the total mechanical energy of a system relationship ?

In an ideal system how does the mechanical energy behaves ?

The mechanical energy remains constant, once on a machine would keep running indefinitely without any energy input

What happens to kinetic energy in real systems with friction?

It is converted into thermal energy and is no longer available as mechanical energy.

Why can’t mechanical devices move continuously without external input?

Because friction dissipates kinetic energy as heat, so energy must be supplied continuously

How is continuous energy supplied to a device?

hrough a drive that adds energy over time, measured as power

What is Power ?