Motion| Worksheet Solutions| Class 9

Worksheet solutions for chapter: Motion for class 9 are provided below.

(1) Write the differences between uniform and non-uniform motion.

Ans- The difference between uniform motion and non – uniform motion are tabulated below –

SN Uniform Motion Non – Uniform Motion
1. When an object covers equal distances in equal interval of time. When an object does not cover equal distance in equal time.
2. Eg:- If an object travels 2 m in 1 sec and next 2 m again in 1 sec. Eg:- Motion in crowd.

If an object travel 2 m in 1 second then it travel 5 m in 2 second.

 

(2) A car starts from the rest. It attains velocity of 10 m/s. It moves 10 s. Calculate its acceleration?

Ans- Initial velocity, u = 0 m/s

Final velocity, v = 10 m/s

Time taken, t = 10 s

Let the acceleration f car = a m/s2

v = u + at

10 = 0 + a(10)

10 = 10a

a = 1 m/s2

Hence, the acceleration of the car is 1 m/s2.

 

(6) Calculate the distance covered by a car in velocity – time graph below-

Diagram of Question 6 of worksheet of NCERT Chapter Motion

(8) An object is moving with velocity of 100 m/s with the acceleration of 6 m/s2. It covers 50 m. What is the initial velocity?

Ans- Final velocity, v = 100 m/s

Acceleration, a = 6 m/s2

Distance cover by the object, s = 50 m

Let the initial velocity = u m/s

v2 – u2 = 2as

1002 – u2 = 2(6) 50

u2 = 10000 – 600

= 9400

u = 96.95 m/s

Hence, initial velocity of the object is 96.95 m/s.

 

(9) Describe velocity – time graph given below –

(a)

Diagram of Question 9(a) of worksheet of NCERT Chapter Motion

(b)

Diagram of Question 9(b) of worksheet of NCERT Chapter Motion

Ans- 

(a) This graph shows uniform acceleration movement of an object.

(b) This graph shows non -uniform acceleration movement of an object.

 

(10) An object starts from rest and attain velocity of 30 m/s in 30 second with acceleration of 1 m/s2. Then it moves 50 m in 2 second. Calculate total distance travelled by the object.

Helping Topics

Motion

NCERT Solutions Class 9