Question

The blades of a moving fan exhibit:
(A) Rotatory motion
(B) Linear motion
(C) Projectile motion
(D) Curvilinear motion

Answer 1

Hint Linear motion is straight line motion, projectile motion is motion under gravity, curvilinear motion is curved line motion and rotatory motion is a spinning motion. We need to investigate which of these is similar to the motion of the blades of the fan and from there we will get the answer.

Complete step by step answer
To answer, we shall study the types of motion of each option and compare to the motion of the blades of a moving fan.
Rotatory motion: This is the motion of a body as it rotates about an axis within itself. It can be said to be the motion of a body as it circulates about a point in itself. Examples of rotatory motion include the rotation of the earth (which causes day and night) and the rotation of a gear in a clock
Projectile motion: This is defined as the motion of a body acting solely under the influence of gravity after being launched above the surface of the earth or any planet. In most cases, it is parabolic except when the object is projected vertically upwards.
Linear motion - this is the motion whose path traces out a straight line such as the motion of a sliding book on a table.
Curvilinear motion: is the motion of any object which traces out a curved line. A parabolic motion is a curvilinear motion.
From these definitions, the most suitable for the motion of the blade of a moving fan is a rotatory motion.
Hence, the correct answer is A.

Note
To avoid confusion, there is a slight difference between circular motion and rotatory motion. While a rotatory motion is a motion of an object about its own axis, a circular motion is the rotation of an object about an axis outside of itself. An example of circular motion is the rotation of an electron in a magnetic field.