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-
(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
u = 96.95 m/s
Hence, initial velocity of the object is 96.95 m/s.
(9) Describe velocity – time graph given below –
(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.