When air resistance is not a factor, all objects near Earth's surface in free fall accelerate downward at approximately:
A6.67 m/s²
B8.33 m/s²
C11.2 m/s²
D9.80 m/s²
Answer & Solution
Correct answer: D. 9.80 m/s²
1. Free fall is the classic example of (nearly) constant acceleration discussed alongside the kinematic equations.
2. The text states directly: "all objects near Earth's surface fall with an acceleration of about 9.80 m/s2."
3. This value is labelled g, the acceleration due to gravity, and is treated as essentially constant near Earth's surface.
4. 6.67 m/s² is close to the gravitational constant's numeric prefix (unrelated units), 8.33 m/s² repeats an earlier train-problem velocity, and 11.2 m/s² is Earth's escape-velocity figure (in km/s) misapplied here -- none is the free-fall acceleration.
5. So the correct value is about 9.80 m/s².
_Source: OpenStax Physics Ch 3 "Acceleration", p.109 §3.2 Representing Acceleration with Equations and Graphs_
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