Question

Translation motion is an example of
A. 1-D motion
B. 2-D motion
C. 3-D motion
D. It may be 1-D, 2-D, 3-D

Answer 1

Hint: If the center of mass of a body shifts from its initial position we say it has undergone a translational motion. It is not compulsory for the object to move in a straight line. In rotation motion this condition is not obeyed. But curvilinear motions like parabolic path is a translational motion.

Complete step-by-step answer:
The shifting of center of mass from its initial position can be considered as translational motion. Translation motion can be curvilinear and also linear. Linear or rectilinear motion is when the object travels along a straight line e.g. ray of light in vacuum. Rectilinear motion is an example of 1D motion. 1 dimensional motion is defined as the motion along a straight line. (Usually in X-axis) Throwing a ball creates a parabolic bath which shows curvilinear motion.

Curvilinear motion can be 2D or 3D. The most cases happening in our daily life are 3D.
A motion is said to be 2 dimensional if it undergoes motion along both x and y axis at the same time. The position in a 2D plane is usually represented by (x,y). Similarly a motion is said to be 3D if it includes movement in all three directions (axis) and its position is usually expressed by (x,y,z).
A flying kite, flying aeroplane, kicking a football from ground etc. show 3 dimensional motion.

There are different types of motion.
Translational
Rotational
Periodic
Non periodic etc.

By so far we can understand that the translational motion can be either 1-D, 2-D or 3-D.

Note: Often people confuse rectilinear motion with translational motion. Rectilinear motion is a special case of translational case.
It is interesting that there is a great analogy between translational and rotational motion. If in translational motion all the particles of the body covers equal distance then in rotational motion every particle undergoes or moves at the same angle. Likewise there are many examples. Moment of inertia is the rotational analog of mass, torque is for force, angular acceleration for acceleration etc.