ΣF = 0An object will continue to move at the same speed in the same direction (or if at rest will remain at rest) unless acted on by a resultant force.An object moves at constant speed in a straight line if there is no resultant force acting on it.An object's motion will not change unless there is a resultant force acting on it to change its motion.The motion of a object is both its speed and direction. So you need a force to change the speed of an object and a force to change the direction of the object.
Newton's First Law of Motion
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Specification: Edexcel Physics (8PH0), AS-level, Topic 2: Mechanics, statements 17 and 20. Topic: Motion.
Key terms in this lesson
- resultant force
- The single force that has the same effect on an object as all the individual forces acting on it combined.
More in Motion
- The Moment of a Force
- Centre of Gravity
- Moments Question 1
- Moments Question 2
- Newton's Second Law of Motion
- Newton's Third Law of Motion
- Constant Acceleration
- Distance from Average Speed
All 31 lessons in Motion · All Edexcel AS-level Physics topics