Chapter 7: Motion

Question 1

What is motion?

Answer 1

If there is a change in the position of an object then the object is said to be in motion

Question 2

Define Distance. Is it a scalar or vector quantity? Can it be zero or negative?

Answer 2

The length of the path followed by an object
It is a scalar quantity
It can’t be zero or negative

Question 3

Define Displacement? Is it a vector or scalar quantity? Can it be zero or negative?

Answer 3

The length of the shortest distance between initial and final position of an object
It is a vector quantity
It can be zero or negative

Question 4

What will happen if the final and initial positions are the same?

Answer 4

If the initial and final positions are same then the displacement is zero

Question 5

What will happen if an object moves in a straight line in the same direction?

Answer 5

If an object moves in a straight line in the same direction then the distance and displacement are same

Question 6

Is the distance always greater than or equal to the displacement?

Answer 6

The distance is always greater than or equal to the displacement

Question 7

What is the ratio of displacement to. The distance ?

Answer 7

The ratio of displacement to the distance is less than or equal to 1

Question 8

Define uniform motion

Answer 8

If an object covers equal distances in equal intervals of time then it is travelling in uniform motion

Question 9

Define non uniform motion

Answer 9

If an object covers equals distances in unequal intervals of time then it is travelling in non uniform motion

Question 10

Define speed

Answer 10

The distance travelled by an object in unit time
Speed=distance/time
Unit=m/s or ms·¹
It is a scalar quantity
Average speed=total distance/total time

Question 11

Define velocity

Answer 11

The rate of displacement of an object
Velocity=displacement/time
Its unit is m/s
It is a vector quantity
Average velocity=initial velocity+final velocity/2

Question 12

Differences between speed and velocity

Answer 12

Speed:
The distance travelled by an object is in unit time
This is a scalar
It can’t be zero
It can’t be negative

Velocity:
The rate of change of displacement over object
It is a vector
It can be zero
It can be negative

Question 13

Define acceleration

Answer 13

The rate of change of velocity of an object
a=v-u/t
v=final velocity
u=initial velocity
t=time
Unit:m/s²
It is a vector quantity
If the velocity increases acceleration is positive
If the velocity decreases acceleration is negative
Negative acceleration is called retardation

Question 14

Define uniform acceleration

Answer 14

If the velocity of an object increases or decreases in equal amounts in equal intervals of time then the acceleration is uniform

Question 15

Define non uniform acceleration

Answer 15

If the velocity of an object increases or decreases by equal amount in unequal interval of time then the acceleration is non uniform

Question 16

If the line over the distance time graph is parallel to the time axis what does it mean?

Answer 16

If the distance time graph of an object is a straight line parallel to time Axis it indicates the object is at rest and its speed is zero

Question 17

What does it mean if the straight line is inclined with the time axis?

Answer 17

If the distance time graph is a straight line inclined with time Axis then the object is moving with a constant speed

Question 18

What does it mean if the distance time graph line is curve?

Answer 18

If the distance time graph is a curve then the object is moving with non uniform motion

Question 19

What does the slope of the distance time graph give us?

Answer 19

The slope of the distance time graph gives us speed

Question 20

What does it mean if the velocity time graph is a straight line parallel to the time axis?

Answer 20

If the velocity time graph is a straight line parallel to the time Axis then the object is moving with uniform velocity and its acceleration is zero

Question 21

Is the velocity time graph is a straight line in the time Axis what does it mean?

Answer 21

If the velocity time graph is straight line inclined with time Axis it indicates the object is moving with uniform acceleration

Question 22

What does the slope of the velocity time graph give us?

Answer 22

The slope of the velocity time graph give us acceleration

Question 23

What does the area under velocity time graph give us?

Answer 23

The area under velocity time graph gives us displacement

Question 24

For uniform motion the distance time graph is a straight line inclined to what?

Answer 24

For uniform motion the distance time graph is a straight line inclined into time axis

Question 25

For non uniform motion the distance time graph is what?

Answer 25

For non uniform motion the distance time graph is a curve

Question 26

What does it indicate?

Answer 26

It's indicate the object is at rest and its speed is zero

Question 27

What does it also indicate?

Answer 27

It also indicate the object is moving with constant speed

Question 28

What are the different displacement equations of motion?

Answer 28

When the object is moving with the constant acceleration in a straight line the different physical quantities are reputed by a set of equations and are given by: v=u+at² s=ut+½at² 2as=v²-u²

Question 29

Define uniform circular motion

Answer 29

One and object is moving in a circular path for the constant speed it is in uniform circular motion. In case of uniform circular motion the distance of velocity and any point is along tangent show direction and its also possessive Stilton acceleration due to change in the velocity of object at different points because of a change in his direction the direction of acceleration is towards the centre of a circular path and recall is centripetal acceleration and its value is found by aç=v²/r The speed of an object in uniform motion is given by v=2πr/r