An object is raised to a height of 3 m from the ground. It is then allowed to fall on to a table 1 m high from ground level. In this context, which one among the following statements is correct ?

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Q: 35 (CDS-I/2015)
An object is raised to a height of 3 m from the ground. It is then allowed to fall on to a table 1 m high from ground level. In this context, which one among the following statements is correct ?

question_subject: 

Science

question_exam: 

CDS-I

stats: 

0,17,33,17,11,12,10

keywords: 

{'potential energy increases': [0, 0, 0, 2], 'potential energy': [0, 0, 1, 4], 'kinetic energy increases': [0, 0, 1, 0], 'ground level': [0, 0, 0, 1], 'height': [0, 0, 1, 2], 'total energy': [0, 0, 1, 4], 'ground': [2, 1, 4, 17], 'thirds': [0, 1, 1, 2], 'third': [2, 1, 3, 6], 'table': [0, 0, 1, 0], 'object': [1, 0, 11, 43]}

Option 1 is correct because potential energy is directly proportional to the height of an object. When the object is raised to a height of 3 m, it has a certain amount of potential energy. However, when it falls onto the table which is 1 m high, its potential energy decreases by two-thirds of its original value. This is because the height decreases from 3 m to 1 m.

Potential energy is given by the formula PE = mgh, where m is the mass of the object, g is the acceleration due to gravity (which we assume to be constant), and h is the height. When the height decreases by two-thirds, the potential energy also decreases by two-thirds.

On the other hand, the kinetic energy of the object will increase as it falls. This is because the object gains speed as it falls downwards, and kinetic energy is given by the formula KE = (1/2)mv^2, where m is the mass of the object and v is its velocity. However, the increase in kinetic energy is not mentioned in any of the options, so option 1 remains the correct answer.

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