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Short Questions

Kinematics

9th Class | Physics | 40 Questions

Question 11

What is meant by the magnitude of a physical quantity?

Answer:
Magnitude is the numerical value of a physical quantity together with its appropriate unit.
Question 12

Why can scalar quantities be added like ordinary numbers?

Answer:
Scalars have magnitude only, so their directions do not need to be considered during addition.
Question 13

Why cannot vectors generally be added like scalars?

Answer:
Vectors have both magnitude and direction, so vector addition must account for direction using a method such as the head-to-tail rule.
Question 14

What are reference axes and origin?

Answer:
Reference axes are two mutually perpendicular lines used to specify direction. Their point of intersection is called the origin.
Question 15

What does the scale of a graphical vector mean?

Answer:
The scale relates a chosen length on paper to the magnitude of the vector, for example 1 cm representing 100 N.
Question 16

Define resultant vector.

Answer:
The resultant is a single vector having the same combined effect as two or more vectors.
Question 17

Why are rest and motion relative concepts?

Answer:
A body may be at rest relative to one observer but moving relative to another, depending on the chosen surroundings or reference point.
Question 18

Define translatory motion.

Answer:
Translatory motion is motion in which every particle of a body moves in the same direction.
Question 19

Name the three types of translatory motion.

Answer:
Linear motion, random motion and circular motion.
Question 20

Define linear motion with an example.

Answer:
Linear motion occurs along a straight line; a freely falling body is an example.