Home › CBSE Class 11 › Physics › Motion in a Straight Line › Per NCERT, can a particle with POSITIVE accelera…
Per NCERT, can a particle with POSITIVE acceleration always be 'speeding up'?
AYes — positive a always means speeding up
BNo — positive acceleration with negative velocity means the particle is slowing down (decelerating in motion sense)
CPositive a is impossible
DAlways opposite to velocity
Answer & Solution
Correct answer: B. No — positive acceleration with negative velocity means the particle is slowing down (decelerating in motion sense)
Per NCERT Exercise 2.7(d) hint, positive a + negative v = decelerating motion. Speeding up requires a·v > 0.
Related questions
A ball is thrown up with initial velocity $u$. It reaches its highest point at time:For a ball thrown vertically upwards and returning to the ground, the velocity-time graph:Displacement differs from distance in that displacement:For uniform motion, velocity is represented by the gradient of a:Which quantities need a sign convention fixed before they are assigned values?In uniform motion, how does instantaneous velocity vary with time?Why can average speed exceed the magnitude of average velocity?Speed differs from velocity in that speed does not carry: