F = m a

________

F = force (N)

m = mass (kg)

a = acceleration (m / s / s) or

 

Mechanics

Mass and weight

Uniform movement

Accelerated movement

Work / energy

Kinetic energy

Power

Momentum

Collisions

Force

Pressure and force

Elastic force (Hooke's Law)

Projectile motion

 

Force

Force is the kind of thing which everybody seem to know what it is.

 Example: Jedis are the ones that have the force!!!

However, in physics,it has a very precise meaning.

According to Newton's Law: F = ma

We can also give a definition:

Force is something that makes an object (or microscopic particle) move or stop to move. On the absence of forces, the object stays as it is , i. e., either moving at a constant speed or stationary.

The important thing to understand from the definition is that a force is not needed to keep an object moving. You only apply a force if you want to stop it or to accelerate it .


In Newtons own words:

"Every object continues in its state of rest, or of uniform motion in a
straight line, unless it is compelled to change that state by forces
impressed upon it."

Newton's first law of movement


 

Examples

1) What force is needed to apply to a car , whose mass is 1000 kg, to provide an acceleration of 10 m/s/s ?

F = m a = 1000*10 = 10000 N

2) What is the force of gravity acting in a person whose mass is 50kg?

acceleration of gravity = g = 10 m/s/s

F = 50 * 10 = 500 N

This force is called weight.

 


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