Question

Choose the wrong statement.

• A. zero-velocity of a particle at any instant does not necessarily mean that its acceleration is zero
• B. zero acceleration of a particle at any instant does not necessarily mean that its velocity is zero
• C. if the speed of a particle is constant, its acceleration must be zero
• D. none of the above

Answer 1

Answer: (C)

When a body is released is gravity.
A body moves with uniform velocity.
If the speed of the particle is constant and
$a-$ acceleration is zero. e.g. of particle moves in a fixed direction. velocity = constant, hence acceleration must be zero.
$b-$ acceleration is non-zero. e.g. A particle undergoes circular motion. accelerating particle is acting radially inward.