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SS1: PHYSICS – 1ST TERM

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  1. Introduction to Physics | Week 1
    4Topics
    |
    1 Quiz
  2. Measurement | Week 2
    3Topics
  3. Measurement of Mass | Week 3
    6Topics
    |
    1 Quiz
  4. Motion | Week 4
    5Topics
    |
    1 Quiz
  5. Velocity-Time Graph | Week 5
    4Topics
    |
    1 Quiz
  6. Causes of Motion | Week 6
    5Topics
    |
    1 Quiz
  7. Work, Energy & Power | Week 7
    3Topics
  8. Energy Transformation / Power | Week 8
    3Topics
    |
    1 Quiz
  9. Heat Energy | Week 9
    5Topics
    |
    1 Quiz
  10. Linear Expansion | Week 10
    6Topics
    |
    1 Quiz
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Any agency that tends to bring about change in motion of an object in a straight line, or tends to keep the object in uniform motion, is called a Force. Examples of forces are push, pull, tension, reaction.

Force can cause a body at rest to move, a moving body to accelerate, move in a curved path, or change direction.

Force is a vector and its SI unit is Newton (N)

One Newton is the amount of force required to give a 1kg mass an acceleration of 1 m/s2

1 Newton = 1 kg m/s2.

Types of Force:

There are two types of force namely; Contact force and Force field (Non-contact force)

Contact Force:

This is a force that interacts with a body and requires contact to occur. Objects that are in contact with each other, exert forces on each other, for example, Push, Pull, Friction, Normal force, Spring force, Tension, are all examples of contact force since they interact, or come in contact, with the body they act on.

contact force

Let’s briefly discuss some contact forces;

a. Frictional Force: This is the force that enables a person to walk without slipping. It is the force that opposes relative motion when two bodies are in contact.

b. Reaction Force: This is another type of Contact force and includes Tension and Upthrust.

c. Tension: If a mass of a body is attached to one end of a string, the string would be observed to stretch and stay strong. The reaction force on the string due to the weight of the mass attached is called Tension.

d. Upthrust: This is a reaction force that acts on a body when it is partially or fully immersed in water. it is the upward reaction force, of the liquid to the weight of the body when immersed.

Force Field (Non-Contact Force)

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A non-contact force is a force that acts on an object, without coming physically in contact with it.

Examples of Force Field include the following;

  • Gravitational Force.
  • Magnetic Force.
  • Electric Force.
  • Nuclear Force.
  • Electrostatic Force.

Let’s briefly discuss some non-contact forces;

Gravitational Force: This is the force of attraction between any two masses, or the force of attraction in which a planet attracts an object towards its centre.

Electrostatic Force: This is the force that exists around a charged body. The body could be positively or negatively charged.

Magnetic force: This is a type of force field that exists around a magnet that has a North and South Pole.

Because a force is a vector that has a direction, it is common to represent force using diagrams, in which a force is represented by an arrow. 

The size of the arrow is reflective of the magnitude of the force, and the direction of the arrow reveals the direction that the force is acting.

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