#### Galileo's law of inertia

A body continues in its state of rest or constant velocity along the same straight line, unless not disturbed by some external force. This is Galileo's law of inertia.

#### Newton's laws of motion

Newton's gives three law of motion:

##### 1. Newton's first law motion

A body continues in its state of rest or constant velocity along the same straight line, unless not disturbed by some external force. This is Newton's first law motion.

##### 2. Newton's second law motion

Time-rate of change of momentum is proportional to the applied external force. This is Newton's second law motion

##### 3. Newton's third law motion

To every action there is always equal and opposite reaction. This is Newton's third law motion.

#### Linear momentum

Linear momentum of a moving particle is given by,

$$ \vec{p} = m\vec{v}$$

Where m is the mass of moving particle with velocity \( \vec{v}\)

#### Force

Force on a particle having mass m is given by,

$$\vec{F} = m\vec{a}$$

Where, \(\vec{a}\) is the acceleration of the particle.

- SI unit of force is Newton ( N ), which is equal to kilogram metre per second ( kg m s
^{-1}).

CGS unit of force is dyne.

## Learn some extra:

### What is the value of 1N in terms of fundamental units?

As we know that,

F = ma

So, 1N = 1 kg × 1m s

^{-2}

Or, 1N = 1 kg m s

^{-2}

So, the value of 1N in terms of fundamental units is 1 kg m s

^{-2}.

### What is the value of 1dyne in terms of cgs units?

As we know that,

F = ma

So, 1dyne = 1 g × 1cm s

^{-2}

Or, 1dyne = 1 g cm s

^{-2}

So, the value of 1dyne in terms of cgs units is 1 g cm s

^{-2}.

### What is the relation between newton and dyne?

As we know that,

F = ma

So, 1N = 1 kg × 1m s

^{-2}

Or, 1N = 10

^{3}g × 10

^{2}cm s

^{-2}

Or, 1N = 10

^{5}g cm s

^{-2}

Or, 1N = 10

^{5}dyne

So, the 1N is equal to 10

^{5}dyne.

#### Impulse

Impulse is given by,

$$ \vec{I} = \vec{F_a} t$$

Where \( \vec{F_a}\) is the average force acts on the particles and t is the time for which the force acts on the particle.