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When a situation involves more than one object, it is important to analyse the motion of:
AEach part in isolation
BThe whole system
COnly the largest part
DOnly the smallest part
Answer & Solution
Correct answer: B. The whole system
1. Multi-object problems need the right choice of system.
2. Newton's laws apply to a defined system.
3. When a situation involves more than one object, it is important to define the system.
4. The motion of a whole system is analysed, not its elements.
5. That analysis is based on external forces on the system.
_Source: OpenStax College Physics for AP Courses 2e (CC BY 4.0), Ch 4 'Dynamics: Force and Newton's Laws of Motion', sections 4.1-4.8_
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