alleryStart learning →A fly hits the windscreen of a moving car. Compared with the force the fly exerts on the windscreen, the force the windscreen exerts on the fly is:
ASmaller in magnitude
BThe same in magnitude
CLarger in magnitude
DZero in magnitude
Answer & Solution
Correct answer: B. The same in magnitude
1. Newton's third law deals with the pair of forces two interacting objects exert on each other.
2. If body A exerts a force on body B, body B exerts a force of equal magnitude on body A.
3. The two forces point in opposite directions but their magnitudes match exactly.
4. The masses of the two bodies play no part in comparing the two forces of the pair.
5. The fly is wrecked and the car is not because the same force produces a huge acceleration on a tiny mass.
6. Choosing the smaller option confuses the damage done with the size of the force, which is the trap set here.
_Source: Siyavula Physical Sciences Grade 11 (Everything Science, CC BY 4.0), Chapter 2: Newton's laws_
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