Question

Short Answer Questions - I: (2 x 4 = 8)
Q.2. Define 'Rest'.
Q.3. Define 'Motion'.
Q.4. Define 'velocity'.
Q.5. Write the differences between speed and velocity.​

Answer 1

Explanation:

Q1

In physics, rest is the state an object being stationary relative to a particular frame of reference or another object; when the position of a body with respect to its surroundings does not change with time it is said to be "at rest".

Q2 .

Movement of any object from one position to another position with respect to the observer is called as Motion.

Q3 .

Velocity is the speed of an object moving in a definite direction. The SI unit of velocity is also metre per second. Velocity is a vector quantity; it has both magnitude and direction.

Q4 .

Speed :

(i) Speed is defined as the distance travelled by the body per unit time .

(ii) speed is a scalar value .

(iii) The SI unit of speed is the metre per second .

Velocity :

(i) Velocity of a moving body is defined as is rate of change of its position with time in a particular direction .

(ii)Velocity is a vector quantity .

(iii) The SI (metric system) as metres per second (m/s) or as the SI base unit of (m⋅s−1).

Answer 2

Explanation:

1. Rest - when a position of an object with respect to its surroundings does not change with time it is said to be 'rest'.
2. Motion - the change in state of position of an object is called its 'motion'.
3. Velocity - the displacement of an object with respect to time is called 'velocity'.
4. Speed - it is a scalar quantity. It is a rate with which object covers distance. Velocity - it is a vector quantity. It is with which position changes.