Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEET
Exam
NEET
Subject
Physics
Chapter
Motion in One Dimension

NEET · Physics · Motion in One Dimension

Assertion : A body of mass 4 kg has an initial velocity (5 i ~m / s...

Assertion : A body of mass 4 kg has an initial velocity (5 \hat{i\mathrm{i}}  m\mathrm{~m}/ s\mathrm{s}). It is subjected to a force of (4 \hat{j\mathrm{j}}  N\mathrm{~N}). The displacement of the body from the origin after 4 s will be 21.5 m. Reason : The equation (v=u+a\mathrm{v}=\mathrm{u}+\mathrm{a}t) can be applied to obtain (v\mathrm{v}), if (a\mathrm{a}) is constant.

Options

  1. AIf both Assertion and Reason are correct and Reason is the correct explanation of Assertion
  2. BIf both Assertion and Reason are correct but Reason is not the correct explanation of Assertion
  3. CIf Assertion is true but Reason is false
  4. DIf Assertion is false but Reason is true

Correct answer

B. If both Assertion and Reason are correct but Reason is not the correct explanation of Assertion

Step-by-step solution

- Assertion: For a particle moving along a straight line, if the velocity is zero at an instant, the acceleration may or may not be zero at that instant. (Correct. e.g., a ball thrown upwards at its peak, (v=\mathrm{v}=0) but (a=g\mathrm{a}=\mathrm{g}). Or a body moving with constant velocity, (v=\mathrm{v}=0, a=\mathrm{a}=0)). - Reason: Acceleration is the rate of change of velocity. (Correct definition). - The reason correctly defines acceleration but does not explain why acceleration may not be zero when velocity is zero at an instant. - Assertion: For a particle moving along a straight line, if the velocity is zero at an instant, the acceleration may or may not be zero at that instant. (Correct. e.g., a ball thrown upwards at its peak, (v=\mathrm{v}=0) but (a=g\mathrm{a}=\mathrm{g}). Or a body moving with constant velocity, (v=\mathrm{v}=0, a=\mathrm{a}=0)). - Reason: Acceleration is the rate of change of velocity. (Correct definition). - The reason correctly defines acceleration but does not explain why acceleration may not be zero when velocity is zero at an instant.
Practice Motion in One Dimension on Quantrex Academy →

More from Motion in One Dimension

A vehicle runs on a straight road of length 'L'. It travels half the distance with speed… MHT CET Medical 2026For uniform acceleration in linear motion which of the following is NOT CORRECT ? MHT CET Medical 2026Two cars, P and Q move toward each other, getting 8\ m closer every second. If they move… MHT CET Medical 2026A block is kept on the floor of an elevator at rest. The elevator starts descending with… MHT CET Medical 2026The acceleration (a ) -time (t ) graph for the body starting from rest is as shown in the… MHT CET Medical 2026A train accelerates from rest at a constant rate 'p' for some time (attains velocity 'v')… MHT CET Medical 2026The following plots show variation of velocity ( v ) with time ( t ), of a ball thrown… NEET 2026Consider a particle moving along a straight line, whose position as a function of time is… NEET 2026 Full Motion in One Dimension list All NEET PYQs