To analyze the effect of decreasing the initial height of an object in free fall, let's consider the concepts of potential energy and total mechanical energy.
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Total Energy: In a closed system (ignoring air resistance), the total mechanical energy of an object consists of its potential energy (due to height) and kinetic energy (due to motion). The principle of conservation of mechanical energy states that the total mechanical energy remains constant if only conservative forces (like gravity) are acting.
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Potential Energy: The potential energy (PE) of an object at height \( h \) is given by the formula \( PE = mgh \), where \( m \) is mass, \( g \) is the acceleration due to gravity, and \( h \) is the height. If the initial height decreases, the initial potential energy decreases.
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Final Velocity: The final velocity of the object just before it hits the ground can be derived from the conservation of energy principle. It can be calculated using the equation that relates potential energy at the height with the kinetic energy at the point just before impact.
Given these points, if you decrease the initial height of the object, you decrease its initial potential energy. However, as energy is conserved, the total mechanical energy of the system will remain the same, but its distribution between potential and kinetic energy will change.
So, the correct statement regarding the effect of decreasing the initial height of an object in free fall is:
The total energy of the object will remain the same.