NEET
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- NEET
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- Physics
- Chapter
- Motion in Two Dimensions
NEET · Physics · Motion in Two Dimensions
Given below are two statements: one is labelled as Assertion (A)...
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): For an oblique projectile fired from the ground, the minimum speed during its flight is equal to the horizontal component of its initial velocity.
Reason (R): The vertical component of velocity becomes zero at the highest point, while the horizontal component remains unchanged throughout the flight.
In the light of the above statements, choose the most appropriate answer from the options given below:
Assertion (A): For an oblique projectile fired from the ground, the minimum speed during its flight is equal to the horizontal component of its initial velocity.
Reason (R): The vertical component of velocity becomes zero at the highest point, while the horizontal component remains unchanged throughout the flight.
In the light of the above statements, choose the most appropriate answer from the options given below:
Options
- ABoth Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
- BBoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
- CAssertion (A) is true but Reason (R) is false.
- DAssertion (A) is false but Reason (R) is true.
Correct answer
B. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
Step-by-step solution
The velocity of an oblique projectile at any instant is the vector sum of its horizontal and vertical components.
The horizontal component of velocity remains constant throughout the flight because there is no horizontal acceleration.
The vertical component of velocity decreases as the projectile ascends, becomes zero at the highest point, and then increases downwards.
Since the total speed is , it will be minimum when .
This happens at the highest point, where the speed is simply , which is the horizontal component of the initial velocity. Thus, Assertion (A) is true.
Reason (R) correctly states that the vertical component becomes zero at the highest point and the horizontal component is unchanged, which perfectly explains why the minimum speed is the horizontal component.
Therefore, both (A) and (R) are true and (R) is the correct explanation of (A).
Answer: Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
The horizontal component of velocity remains constant throughout the flight because there is no horizontal acceleration.
The vertical component of velocity decreases as the projectile ascends, becomes zero at the highest point, and then increases downwards.
Since the total speed is , it will be minimum when .
This happens at the highest point, where the speed is simply , which is the horizontal component of the initial velocity. Thus, Assertion (A) is true.
Reason (R) correctly states that the vertical component becomes zero at the highest point and the horizontal component is unchanged, which perfectly explains why the minimum speed is the horizontal component.
Therefore, both (A) and (R) are true and (R) is the correct explanation of (A).
Answer: Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).