Question 1

Q1: Calculate the speed of a car that travels 150 metres in 10 seconds. Express your answer in km/h.

Accepted Answer

Given: Distance $= 150 	ext{ m}$ Time $= 10 	ext{ s}$ To Find: Speed in $	ext{km/h}$ Formula: $$	ext{Speed} = \frac{	ext{Distance}}{	ext{Time}}$$ Calculation: $$	ext{Speed} = \frac{150 	ext{ m}}{10 	ext{ s}} = 15 	ext{ m/s}$$ To convert $	ext{m/s}$ to $	ext{km/h}$, we multiply by $\frac{...

Question 2

Q10: Data for the motion of an object are given in the following table. State whether the speed of the object is uniform or non-uniform. Find the average s...

Accepted Answer

The speed is non-uniform because the object covers unequal distances in equal intervals of time (10 seconds). Given: Total distance $= 60 	ext{ m}$ Total time $= 100 	ext{ s}$ To Find: Average speed Formula: $$	ext{Average Speed} = \frac{	ext{Total Distance}}{	ext{Total Time}}$$ Calculation: $$...

Question 3

Q11: A vehicle moves along a straight line and covers a distance of 2 km . In the first 500 m , it moves with a speed of $10 \mathrm{~m} / \mathrm{s}$ and...

Accepted Answer

Given: Total distance $= 2 	ext{ km} = 2000 	ext{ m}$ Total time $= 200 	ext{ s}$ Distance 1 $= 500 	ext{ m}$ Speed 1 $= 10 	ext{ m/s}$ Distance 2 $= 500 	ext{ m}$ Speed 2 $= 5 	ext{ m/s}$ Distance 3 $= 2000 - 500 - 500 = 1000 	ext{ m}$ To Find: Speed 3 and Average Speed Calculations: Time 1...

Question 4

Q2: A runner completes 400 metres in 50 seconds. Another runner completes the same distance in 45 seconds. Who has a greater speed and by how much?

Accepted Answer

Given: Runner 1: Distance $= 400 	ext{ m}$ Time $= 50 	ext{ s}$ Runner 2: Distance $= 400 	ext{ m}$ Time $= 45 	ext{ s}$ To Find: Who has greater speed and by how much Formula: $$	ext{Speed} = \frac{	ext{Distance}}{	ext{Time}}$$ Calculation: Speed of Runner 1: $$S_1 = \frac{400 	ext{ m}}{50...

Question 5

Q3: A train travels at a speed of $25 \mathrm{~m} / \mathrm{s}$ and covers a distance of 360 km . How much time does it take?

Accepted Answer

Given: Speed $= 25 	ext{ m/s}$ Distance $= 360 	ext{ km} = 360000 	ext{ m}$ To Find: Time taken Formula: $$	ext{Time} = \frac{	ext{Distance}}{	ext{Speed}}$$ Calculation: $$	ext{Time} = \frac{360000 	ext{ m}}{25 	ext{ m/s}} = 14400 	ext{ s}$$ Converting seconds to hours: $$	ext{Time} = \fr...

Question 6

Q4: A train travels 180 km in 3 h . Find its speed in: (i) $\mathrm{km} / \mathrm{h}$ (ii) $\mathrm{m} / \mathrm{s}$ (iii) What distance will it travel in...

Accepted Answer

Given: Distance $= 180 	ext{ km}$ Time $= 3 	ext{ h}$ (i) To Find: Speed in $	ext{km/h}$ Formula: $$	ext{Speed} = \frac{	ext{Distance}}{	ext{Time}}$$ Calculation: $$	ext{Speed} = \frac{180 	ext{ km}}{3 	ext{ h}} = 60 	ext{ km/h}$$ Final Answer: The speed of the train is $60 	ext{ km/h}$....

Question 7

Q5: The fastest galloping horse can reach the speed of approximately $18 \mathrm{~m} / \mathrm{s}$. How does this compare to the speed of a train moving a...

Accepted Answer

Given: Speed of horse $= 18 	ext{ m/s}$ Speed of train $= 72 	ext{ km/h}$ To Find: Comparison of speeds Calculation: Convert the speed of the train to $	ext{m/s}$: $$	ext{Speed of train} = 72 	imes \frac{5}{18} 	ext{ m/s} = 20 	ext{ m/s}$$ Final Answer: The train is faster than the horse. The...

Question 8

Q6: Distinguish between uniform and non-uniform motion using the example of a car moving on a straight highway with no traffic and a car moving in city tr...

Accepted Answer

Uniform Motion: Uniform motion is when an object moves along a straight line with a constant speed. This means the object covers equal distances in equal intervals of time. A car moving on a straight highway with no traffic can be an example of uniform motion if the driver maintains a constant speed...

Question 9

Q7: Data for an object covering distances in different intervals of time are given in the following table. If the object is in uniform motion, fill in the...

Accepted Answer

In uniform motion, the object covers equal distances in equal intervals of time. Here, in every 10 seconds, the object is covering a distance of 8 metres. \begin{tabular}{|l|c|c|c|c|c|c|c|c|} \hline Time (s) & 0 & 10 & 20 & 30 & 40 & 50 & 60 & 70 \ \hline Distance (m) & 0 & 8 & 16 & 24 & 32 & 40 &...

Question 10

Q8: A car covers 60 km in the first hour, 70 km in the second hour, and 50 km in the third hour. Is the motion uniform? Justify your answer. Find the aver...

Accepted Answer

The motion is not uniform because the car covers unequal distances in equal intervals of time (each hour). Given: Distance in first hour $= 60 	ext{ km}$ Distance in second hour $= 70 	ext{ km}$ Distance in third hour $= 50 	ext{ km}$ Total time $= 3 	ext{ hours}$ To Find: Average speed Formula:...

Question 11

Q9: Which type of motion is more common in daily lifeuniform or non-uniform? Provide three examples from your experience to support your answer.

Accepted Answer

Non-uniform motion is more common in daily life. This is because it is rare for objects to maintain a constant speed over long periods. Here are three examples: 1.  A bicycle ride: When riding a bicycle, one constantly adjusts speed based on the terrain, traffic, and energy levels. The speed is not...

NCERT Solutions