Direction: In the following questions, a statement of assertion (A) i...
When a particle is released from rest, υ = 0 but a ≠ 0
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Direction: In the following questions, a statement of assertion (A) i...
A. Statement of Assertion: A body is momentarily at rest when it reverses the direction.
Statement of Reason: A body cannot have acceleration if its velocity is zero at a given instant of time.
The correct answer is option C, which states that assertion (A) is true but reason (R) is false.
Explanation:
When a body is momentarily at rest, it means that its velocity becomes zero for a very short duration of time. This can happen when the body changes its direction of motion. In other words, at the moment it reverses its direction, the body's velocity becomes zero.
Reason (R): A body cannot have acceleration if its velocity is zero at a given instant of time.
Acceleration is the rate of change of velocity with respect to time. If the velocity of a body is zero at a given instant of time, it means that there is no change in its velocity at that moment. Therefore, the body cannot have acceleration at that instant.
Explanation of the Reason:
The reason given is incorrect because a body can have acceleration even if its velocity is zero at a given instant of time. Acceleration is the change in velocity, and velocity is a vector quantity that includes both magnitude and direction. Even if the magnitude of the velocity is zero, the direction can change, resulting in acceleration.
For example, if a car is moving in the positive x-direction with a velocity of 20 m/s and then suddenly stops, its velocity becomes zero. At this point, the car's acceleration is non-zero because it experienced a change in velocity. The acceleration is directed in the negative x-direction.
Therefore, the reason given in the statement is false, and the correct answer is option C.
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