alleryStart learning →Why does the speed stop changing once the net force on a falling body is zero?
ABecause gravity switches itself off
BBecause no acceleration is produced
CBecause the mass becomes zero
DBecause drag reverses direction
Answer & Solution
Correct answer: B. Because no acceleration is produced
1. Newton's second law ties acceleration directly to the net force on a body.
2. With a zero net force there is no acceleration.
3. No acceleration means the velocity cannot change from that moment on.
4. So the body carries on at a steady speed, which is the terminal velocity.
_Source: OpenStax College Physics (CC BY 4.0), Ch 5 "Further Applications of Newton's Laws: Friction, Drag, and Elasticity", section 5.2 Drag Forces_
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