Edexcel A Level Maths: Mechanics:复习笔记3.1.2 Equilibrium in 1D
Equilibrium in 1D
What is Newton’s First Law of Motion (N1L)?
- An object at rest will stay at rest, and an object moving with constant?velocity?will continue to move with constant velocity, unless an unbalanced force acts on the object.
What is the resultant force and an unbalanced force?
- The?resultant?force?is the?sum?of?forces?acting on a particle – consider it as a?single?force?that achieves the?same?result?as?all?the forces?combined
- An?unbalanced?force?is a force acting on a particle that is?not?cancelled by another force acting in the opposite direction
- So a?non-zero?resultant force will be unbalanced (hence the wording in Newton’s First Law of Motion) and the particle will?accelerate
What does equilibrium mean?
- A?particle?is in?equilibrium?if the?resultant?force?acting on it is?zero
- In other words when the?sum?of?the?forces?acting on a particle is zero
- For example, in the?horizontal?direction, any?forces?acting to move the particle to the?left?will be?balanced?by any?forces?acting to move the particle to the?right.
- There does not need to be the same number of forces in both directions – two forces could be acting to move the particle to the left but are cancelled out by only one force acting to move the particle to the right.
Worked Example
Exam Tip
- It is unlikely you will get an exam question that only deals with one dimension at AS and A level.? However two-dimensional problems can often be broken down into two one-dimensional problems so the principles in this note are important to understand.
转载自savemyexams
国际竞赛真题资源免费领取
美高学分项目重磅来袭！立即了解
