InterviewSolution
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An aeroplane touches down at 225 km/h and stop after 20 min calculate length of runway |
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Answer» Answer: Length of RUNWAY = 3.752 km. Explanation: Given: Initial velocity of aeroplane = 225 km/hr Time taken to stop = 2 minutes. To FIND: Acceleration and length of the runway Formulas used: Let u => initial velocity, V => FINAL Velocity , a => acceleration ,t => time and s => distance 1. v = u + at 2. v² = u² + 2as Conversion: 225 km = 225 × (5/18) = 62.5 m/s and 2 minutes = 120 seconds. Calculation: v = u + at => at = v - u => a = (v-u)/t => a = (0 - 62.5) /120 => a = - (62.5/120) => a = - 0.520 m/s²1) Putting value of "a" in eq (2) v² = u² + 2as => 0² = (62.5)² + 2 × (-0.520) × s => 1.041 × s = 3906.25 => s = 3752.4 metres = 3.752 km. So final answer is : Acceleration is -0.520 m/s² and Length of runway = 3.752 km Negative sign in acceleration DENOTES retardation. |
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