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Home > Physics > Revision videos > Newton's first law

Physics

Newton's first law

Newton's first law video

Newton’s First Law is about balanced and unbalanced forces. This video demonstrates how these forces affect the motion of an object.

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Key points

  • Forces are said to be balanced if there are equal forces acting in opposite directions.
  • Balanced forces are equivalent to no force at all.
  • If there are no forces on an object or the forces are balanced, the object's speed does not change - it will be at rest or moving at a constant speed.
  • If the forces on an object are unbalanced, the object will either accelerate or decelerate.
  • Friction and air resistance are forces which oppose motion.

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