Falling object: time before it reaches the ground and its position

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SUMMARY

The discussion focuses on calculating the time it takes for a flowerpot to fall from a height of 20.0 meters and the distance it can fall before a warning reaches a man standing below. Using the formula for free fall, d = 1/2gt², the flowerpot takes approximately 1.93 seconds to reach the ground. The sound of the warning takes about 0.053 seconds to travel to the man, and with a reaction time of 0.300 seconds, the flowerpot can fall 12.2 meters before the man can react, leaving it 7.8 meters above the sidewalk when he hears the warning.

PREREQUISITES
  • Understanding of kinematic equations, specifically d = 1/2gt²
  • Knowledge of sound speed at 20°C, approximately 343 m/s
  • Basic concepts of reaction time in physics
  • Familiarity with free fall motion and gravitational acceleration
NEXT STEPS
  • Study advanced kinematic equations for varying conditions
  • Learn about the effects of air resistance on falling objects
  • Explore sound propagation in different mediums and temperatures
  • Investigate real-world applications of free fall calculations in safety engineering
USEFUL FOR

Physics students, educators, and anyone interested in the dynamics of falling objects and sound propagation in real-world scenarios.

ellyb
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A flowerpot is knocked off a balcony 20.0m above the sidewalk and falls toward an unsuspecting 1.75-m tall man who is standing below. How close to the sidewalk can the flowerpot fall before it is too lat for a warning shouted from the balcony to reach the man in time? Assume the man below requires 0.300s to respond to the warning.
d=1/2gt2
18.25m=4.9t2
1.93s=t for flowerpot to fall
v=d/t
v=343m/s at 20C
343=18.25/t
t=.053s for sound to reach man
So, tflower=tlast instant+tsound+treaction
1.93=.053+.3+t
1.577s=t
okay, d=1/2gt2
d=4.9(1.5772)
12.2m=dCan someone help me i am not sure if i did it right?
 
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that seems gd to me. it has fallen 12.2m so it will be 7.8m above the sidewalk
 

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