Moderate

If the velocity is doubled then the K.E of the body will be:

Correct answer: D. Four times

  • A. Remain same
  • B. Double
  • C. Three times
  • D. Four times

Explanation

The kinetic energy (KE) of an object is given by the formula: KE = (1/2) m x v2 where m is the mass of the object and v is its velocity. Let's consider the options one by one: a) Remain the same: If the velocity is doubled, the kinetic energy will not remain the same. According to the formula, the kinetic energy is directly proportional to the square of the velocity. So, any change in velocity will result in a change in kinetic energy. b) Double: If the velocity is doubled, the kinetic energy will not double. Instead, it will increase by a factor of four. This is because the kinetic energy is proportional to the square of the velocity. When the velocity is doubled, the new kinetic energy will be (22) = 4 times the original kinetic energy. c) Three times: If the velocity is doubled, the kinetic energy will not triple. As mentioned earlier, the kinetic energy is proportional to the square of the velocity. Thus, doubling the velocity will result in a fourfold increase in kinetic energy, not threefold. d) Four times: This is the correct option. When the velocity is doubled, the kinetic energy will increase by a factor of four. The new kinetic energy will be (22) = 4 times the original kinetic energy. Therefore, the correct answer is d) four times.

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About Work and Energy

Work transfers energy when a force causes displacement, while kinetic energy, gravitational potential energy and power describe motion, position and the rate of energy transfer. The work-energy theorem links net work with change in kinetic energy, and efficiency accounts for energy losses rather than treating them as energy destruction.

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