Forces By Mjay and Roxana

What is a Force? A force is a push or pull acting upon an object which involves strength or energy as an attribute of physical action or movement.

There are 5 Different types of forces: Applied Force Gravitational Force (Weight) Normal Force Friction Force Air resistant Force

Applied Force An applied force is a force that is applied to an object by a person or another object. For example, when a ball starts rolling as a result of someone pushing it with his or her hand then there is an applied force acting upon the object. The applied force is the force exerted on the ball by the person.

Gravity Force (Weight) The weight of an object determines the pull of gravity. Everything on earth is being pulled by gravity to the centre of earth, which is called a “downward” pull. This is the reason for why things don’t float and a stationed on the ground naturally. The force of gravity on earth is always equal to the weight of the object. As found by the equation: Fgrav = m * g where g = 9.8 N/kg (on Earth)and m = mass (in kg)

Normal Force The normal force is an object’s positioning being supported by the force of another object. For example, if a ball is sitting on a surface, then the surface is exerting an upward force upon the ball in order to support the weight of the ball. On occasions, a normal force is exerted horizontally between two objects that are in contact with each other. For example, if a person leans against a wall, the wall pushes horizontally on the person to support the persons weight.

Friction Force The friction force is the force that is applied to an object which moves in a way that the surface of an object is rubbing against another. There are at least two types of friction force - sliding and static friction. Thought it is not always the case, the friction force often opposes the motion of an object. E.g. if a ball slides across the surface of a Field, then the Field exerts a friction force in the opposite direction of Its motion.

Air Resistance Force The air resistance Force is a force that is present when objects are moving through the air as a result of another force such as applied or normal. The force of air resistance is often present to go against an object/person. This force will frequently be abused due to its small magnitude e.g., a skydiver or a downhill skier or for objects with large surface areas.

Cycling Forces that apply to cycling are: - A = Gravity force; The weight of the bike and the person on the bike is being pulled to the centre of the earth in a “downward” action. B= Friction Force; This shows the surface of the wheels coming into contact with the ground and rubbing against each other. C= Air Resistance Force; shows the bike moving through the air as a result of different forces/actions applied.

Netball Forces that apply to netball are: Gravity Force: this is present when the ball falls into the hoop, due to the “downward” gravitational pull. Air resistance Force: this is present when the ball is travelling through the air towards the hoop. Applied Force : This is present when the person has applied her natural force towards the ball, causing it to change position (go into the hoop)

References http://www.physicsclassroom.com/Class/newtlaws/u2l2b.cfm http://www.skwirk.com.au/p-c_s-4_u-466_t-1403_c-5406/TAS/6/Applied-force/T.. http://en.wikipedia.org/wiki/Force