Science 8 🫶

• Displacement


  Gap between initial position and the final position of an object
• Velocity


  The speed at which an object moves in one direction
• Acceleration


  The time rate of change of the velocity of the object
• Force


  Push and Pull applied to an object, influence that changes the motion of an object
• Magnitude


  Refers to how strong the force is
• The greater the magnitude


  The faster the velocity
• Newton (N)


  MKS or the Meter-Kilogram-second system (Named after Sir Isaac Newton)
• Dyne (DYN)


  CGS or the Centimeter-Gram-Second system
• Pound (LBS)


  FPS or Foot-pound-Second system
• Direction


  Refers to the points where the object goes
• Point of Application


  The location where the force is applied
• Line of Action


  Straight line passing through the point of Application and is parallel to the direction of the force
• Types of Force


  • Contact Forces
  • Non-Contact Forces
• Contact Forces


  An object needs physical contact to another object
• Contact Forces


  • Applied
  • Friction
  • Normal
  • Tension
• Applied Force


  Refers to the force exerted by a person or an object towards another person or object
• F


  Symbol of Force, depending on who or what applies the force we write it smaller next to the letter F
• Eukaryotes have a true nucleus and other membrane-bound organelles.
• Non-contact forces

  Forces where objects do not touch or are not in contact with each other
• Examples of non-contact forces

  • Gravitational force
  • Magnetic force
• Gravitational force


  The force that attracts objects towards the earth
• Without gravitational force


  Everything will float, many things would be very challenging to do
• Normal force


  The force that acts perpendicular to the surface which an object is in contact with
• With an upward force and an object at rest


  There is also a downward gravitational force that pulls it downwards
• Magnetic force


  The force that is exerted in a field of attraction or repulsion
• Magnetic attraction does not take place with the same poles, only between opposite poles
• Magnets don't necessarily need to be in contact with other magnetic materials to make them move</b>
• Balanced forces


  Forces of opposite directions and equal in magnitude
• Unbalanced forces


  Forces in opposite direction and unequal in magnitude
• Net force/Resultant force


  The sum of all the forces that act on an object
• To solve net force


  1. Use the formula: net force = sum of all forces

  2. Use positive and negative signs to indicate direction of forces
• Pound is not a unit of force
• Gravitational force pulls an object towards the earth
• Friction force is always directed opposite to the motion of the object
• Net force is the sum of the existing forces in the same line of action
• Positive sign is used for forces directed to the right, negative for left
• If net force is not zero, the forces are unbalanced
• If one force is 20N right and another is 15N left, net force is 5N right
• If upward force is 5N and downward force is 5N, net force is 0N
• In the picture, the net force is -20N