Read the assertion and reason carefully to mark the correct option ou...
As a man jumps-out from a height in air with a parachute, its velocity increases first, because the gravity pull dominates the viscous drag and buoyancy of air which opposes the motion. As the velocity increases, the viscous drag of air also increases and soon a stage is reached where viscous drag and buoyancy of air balances the gravity pull. Then the man with a parachute falls with a constant velocity, called terminal velocity.
View all questions of this test
Read the assertion and reason carefully to mark the correct option ou...
Understanding the Assertion and Reason
The assertion states that "the velocity of fall of a man jumping with a parachute first increases and then becomes constant." This is a true statement. When a person jumps from a height, gravity initially causes them to accelerate downwards. However, as the parachute opens, air resistance increases, eventually balancing the gravitational force.
Explanation of Terminal Velocity
The reason provided states, "the constant velocity of fall of man is called terminal velocity." This is also true. Terminal velocity is the maximum velocity an object reaches when the force of gravity is balanced by the drag force of air resistance, resulting in no further acceleration.
Connection Between Assertion and Reason
- The assertion describes the initial behavior of a person falling with a parachute, where the velocity increases due to gravity until the parachute opens.
- Once the parachute opens, the velocity stabilizes due to the balance of forces, leading to terminal velocity.
Why Option B is Correct
- Both the assertion and reason are true.
- The reason correctly explains the concept of terminal velocity but does not directly explain the initial increase in velocity mentioned in the assertion. The assertion focuses on the change in velocity before the parachute stabilizes the fall.
Thus, option B is correct: both the assertion and reason are true, but the reason is not the correct explanation of the assertion.
To make sure you are not studying endlessly, EduRev has designed Class 11 study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Class 11.