Science - Physics

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Science - Physics
2010-11-01 02:12:05

Forces: Thrust, Friction, Lift & Gravity
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  1. What is physics?
    Physics deals with questions about electricity, energy, magnetism and forces.
  2. What did Ernest Rutherford become the first person to discover?
    He was the first person to discover that: every atom is mostly empty space. And that every atom has a small, dense, positively charged center called a nucleus.
  3. What is a force?
    A force is a push or pull.
  4. What is force measured in?
    Force is measured in Newtons (N).
  5. What occurs when forces are balanced?
    When forces are balanced there is either no movement or the object travels at a constant speed.
  6. What occurs when the forces are unbalanced?
    When the forces are unbalanced the object is either accelerating or decelerating.
  7. What are the names of the four forces?
    The four forces are: Thrust (Push), Friction (Pull), Lift/Support (Up) and Gravity/Weight (Down).
  8. What is weight?
    Weight is the force that an object is attracted towards. It differs when the gravitational force changes. A spring balance measures weight.
  9. What is mass?
    Mass is the amount of matter in a body, and is also the space an volume the body takes up. The mass of an object does not change. Mass is weighed by an ordinary weighing balance.