Forces

This term in science I am learning about forces.
Throughout the mechanics section in my scipad, I have learnt various formulas, how different forces work, how they are measured and how they work with one another. The subjects I have covered so far are balanced and unbalanced forces, force mass and acceleration, mass and weight, air resistance and pressure.
I think I miss calculated my answers a few times but quickly corrected them. I now have a deeper understanding of these forces but still, and will always, have room to learn.


Force:

force¹

/fɔːs/

Learn to pronounce

noun

1. 1.

   strength or energy as an attribute of physical action or movement.

   
   

   "he was thrown backwards by the force of the explosion"

Force is a push or pull, causing an object to undergo a change in speed, direction or shape. we are unable to see force directly but can see what it does. Force can make objects move, increase or decrease velocity, change the direction an object is moving and can change the shape of an object. Force is measured in Newtons. 

Sir Isaac Newton:

Sir Isaac Newton, 1643-1727, was an English physician and mathematician. He was the first to create a measure of force and understand gravity.

Mass and weight:

Mass and weight are typically confused. It is widely thought that weight is measured in kilograms when it is actually measured in Newtons.

Mass: mass is the amount of matter found in an object. Mass is measured in Kilograms (kg).
Weight: Weight is the force of gravity acting upon an object, determined by an objects mass. Weight is measured in Newtons (N).

When working out the weight of an object, we use the equation F=ma, or force = mass* acceleration.

Friction:

Friction is the force that occurs when an object moves through/against another object or fluid.Friction often acts to stop or prevent an object moving. Friction causes wear and tear, generates heat and slows a moving object down.
Drag is the friction force acting upon an object when moving through a fluid (gas or liquid).




Air resistance:

Air resistance is the friction between the air and a moving object. Air molecules get caught on the surface of the object, slowing down or stopping it's movement. the larger the surface area, the greater the air resistance.



Pressure:

Pressure is how much force is exerted onto a particular area. The formula for pressure is P=F/A and pressure is measured in Nm-2 or 'Newtons per Square meter'. If the force is the same, a smaller area would generate more pressure than a large area which has its pressure spread out. When the area is smaller (eg, high heels) the force is concentrated and the pressure is greater. Scissor blades have very little surface area, creating more pressure and cutting through other objects.