Question

A helicopter is moving in a straight path. Which type of motion with the propeller of a helicopter executes?
A) Rotatory motion
B) Oscillatory motion
C) Translators motion
D) Both A) and C)

Answer 1

Hint : linear motion is the type of motion where a body moves along a straight line path in one direction only. The body only has a one dimensional axis of motion in this case. A good example of linear motion is the falling of a stone when it is dropped from a height. It moves in a straight line path in the downward direction and hence performs linear motion.

Complete step-by-step solution:
Propeller is a device which as a rotating hub and radiating blades that are set at a pitch to form a helical spiral, that, when rotated, performs an action and it transforms rotational power into linear thrust by acting upon a working fluid,
Rotational motion: A rotation is defined as circular movement of an object around a center to a point of rotation. An object which is three dimensional can always be rotated about an infinite number of imaginary lines which are called axes. If the axis passes through the center of mass of the body. The body is said to be rotating upon itself or spinning. Rotation around an external point, for example, the planet Earth which revolves around the sun, is called a revolution or an orbital revolution, especially when it is produced by gravity. This axis is termed a pole.
Motions of the propeller of a flying helicopter executes rotatory motion
So the correct option is A.

Note: In rotational motion, a body remains fixed at one point in space and rotates about an internal axis. However, on the other hand, in circular motion, the body moves in space in such a way that it follows a circular path. In doing so, the body may or may not rotate about an internal axis, that is, it may not perform rotational motion.