LEVELJEE Main
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The Sigma Insight: Kinetic Energy, Potential Energy and Power
An athlete sprinting down a track is a beautiful display of biomechanics and physics in action. But how do we quantify the energy of such a dynamic event when we aren't given all the variables? This problem is a brilliant exercise in estimation—a crucial skill for any physicist.
Analyzing the Setup
We are told that an Olympic athlete covers a distance of m in s. We need to find the range of his kinetic energy. The formula for kinetic energy is:
To use this formula, we need two quantities: the mass () of the athlete and his velocity (). We can easily find the average velocity using the given distance and time:
The Art of Estimation
Here is where the problem tests your real-world intuition. We are not given the mass of the athlete. However, we know that an average adult human, especially a sprinter, typically weighs somewhere between kg and kg. Let's assume a reasonable average mass of kg.
Final Calculation
Now, we substitute our estimated mass and calculated velocity into the kinetic energy equation:
Our estimated kinetic energy is Joules. Now, let's look at the given options. The value J falls perfectly within the range of J to J.
Even if we had assumed a slightly different mass, say kg, the kinetic energy would be J, which still comfortably sits in the same range. This shows the robustness of our estimation. Therefore, the correct option is (d).
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