What Is the Takeoff Speed of an Aircraft Based on a Watch's Angle?

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SUMMARY

The takeoff speed of an aircraft can be estimated using the angle of a dangling watch during acceleration. In this discussion, Francesca observed the watch making a 25° angle with the vertical while the aircraft accelerated at JFK Airport. By applying the tangent function, the acceleration was calculated to be 4.57 m/s². Using the formula V = Vo + at, the estimated takeoff speed is determined to be approximately 82.2 m/s, equating to around 300 km/h, which is a realistic figure for aircraft takeoff speeds.

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  • Knowledge of kinematic equations, particularly V = Vo + at
  • Basic understanding of units of measurement in physics (m/s, km/h)
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Francesca dangles her watch from a thin piece of string while the jetliner she is in takes off from JFK Airport. She notices that the string makes an angle of 25° with respect to the vertical while the aircraft accelerates for takeoff, which takes about 18s. Estimate the takeoff speed of the aircraft.

k so you know that the force of gravity is mg and it's going down, and that the acceleration is ma along the horizontal, and so can you take the tan(25)=a/9.8 to get an acceleration of 4.57m/s^2?

And so for velocity you would get V=Vo+at
V=0+(4.57)(18)
V=82.2m/s?

thanks for reading
 
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It seems to be correct. Which means the take-off speed is around 300 km/h which is realistic.
 
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