Question 201: Work, Energy and Power & Circular Motion

Question

For a particle moving in a circle with constant angular speed, which of the following statements is 'false'?

Accepted Answer

We first recall some basic facts from
Uniform Circular Motion (UCM):
The particle is moving with
constant angular speed
.
Its
velocity
is always
tangent to the circle
.
The
acceleration
is called centripetal acceleration, and it always points
towards the centre of the circle
.
The acceleration is
perpendicular
to the velocity.
Now let us check each option:
Option A:
Ã¢ÂÂThe velocity vector is tangent to the circle.Ã¢ÂÂ
Ã¢ÂÂ This is
true
.
Option B:
Ã¢ÂÂThe acceleration vector is tangent to the circle.Ã¢ÂÂ
Ã¢ÂÂ This is
false
, because acceleration is directed towards the centre, not tangent.
Option C:
Ã¢ÂÂThe velocity and acceleration vectors are perpendicular to each other.Ã¢ÂÂ
Ã¢ÂÂ This is
true
.
Option D:
Ã¢ÂÂThe acceleration vector points to the centre of the circle.Ã¢ÂÂ
Ã¢ÂÂ This is
true
.
Correct Answer: Option B

Answer

The velocity vector is tangent to the circle.

Answer

The acceleration vector is tangent to the circle.

Answer

The velocity and acceleration vectors are perpendicular to each other.

Answer

The acceleration vector points to the centre of the circle.

Work, Energy and Power & Circular Motion

For a particle moving in a circle with constant angular speed, which of the following statements is 'false'?

Choose the correct answer: