Types of force

Introduction to Force

In Physics, a force is simply a push or a pull on an object. Think about when you push a heavy bag of garri across the floor or when you pull a bucket of water up from a borehole. You are applying force.

Basically, force is what makes things move, stop, or change direction.

Contact Forces

These are forces that happen when two objects are physically touching each other. Examples include:

Frictional Force: This is the force that opposes motion between two surfaces rubbing together, like your slippers rubbing against the ground.

Tension: This is the pull transmitted through a rope or string, like the wire holding a NEPA pole or a rope used to tow an okada.

Normal Force: This is the upward support force from a surface, like a table pushing up on a textbook so it doesn't fall through.

Reaction Force: The force that pushes back when you press against something.

Non-contact or Field Forces

These are forces that act even when objects are not touching. They work through a space called a field. Examples include:

Gravitational Force: This is the pull of the Earth on objects. It is why a mango falls from a tree to the ground.

Magnetic Force: The force between magnets or between a magnet and a piece of iron.

Electrostatic Force: The force between electric charges, like when you rub a plastic ruler in your hair and it picks up small bits of paper.

Weight as a Force

Weight is a specific type of gravitational force. It is the pull of the Earth on your mass. Do not confuse weight with mass! Mass is the amount of matter in you, while weight is a force measured in Newtons (N).

Weight is calculated by multiplying mass by the acceleration due to gravity (g = 9.8 or 10 m s^-2).

Worked Example

Calculate the weight of a student whose mass is 55 kg. (Take g = 10 m s^-2)

1. Identify the given values: Mass (m) = 55 kg, Gravity (g) = 10 m s^-2.

2. Use the formula: Weight (W) = m x g.

3. Substitute the values: W = 55 x 10.

4. Final answer: W = 550 N.