A farmer moves along the boundary of a rectangular field ABCD as shown in the figure. He takes 4 minutes to travel across each side. Is the motion of this farmer uniform or non-uniform? Find his average speed over one complete round of the field.

The average speed of a moving object is defined as the total distance covered by it is divided by the total time taken. It is a scalar quantity. In this case, it takes the farmer 4 minutes to travel around each side of the rectangular shape field. The distances travelled on each side will now be calculated as follows: Given distances are- AB = 80 m BC = 40 m CD = 80 m DA = 40 m The farmer's motion is non-uniform since the distances traveled on each side differ. The distances traveled at equal time intervals are not equal in non-uniform motion. Calculate the entire distance traveled and divide it by the total time taken to get the average speed for one complete round of the field. Total distance traveled = AB + BC + CD + DA Total distance traveled = 80 m + 40 m + 80 m + 40 m Total distance traveled = 240 m Total time taken = 4 minutes × 4 sides Total time taken = 16 min Now, we will convert the total time taken into seconds. Total time taken = 16 minutes × 60 seconds / minute Total time taken = 960 seconds Average speed = Total distance traveled Total time taken Average speed = 240 m 960 seconds Average speed = 0 . 25 m s - 1 The farmer's average speed over the full round of the field is therefore approximately 0 . 25 m s - 1 .

EASY

7th CBSE

IMPORTANT

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Draw the shape of a distance-time graph for a man, walking on a level, straight and narrow road, at a constant speed.

Important Questions on Motion and Time

EASY

7th CBSE

IMPORTANT

The Living World A book of Science and Technology>Chapter 6 - Motion and Time>Something To Know>Q 1

A farmer moves along the boundary of a rectangular field ABCD as shown in the figure. He takes $4$ minutes to travel across each side.
Question Image
Is the motion of this farmer uniform or non-uniform? Find his average speed over one complete round of the field.

EASY

7th CBSE

IMPORTANT

The Living World A book of Science and Technology>Chapter 6 - Motion and Time>Something To Know>Q 2

During rainy season, Shivam noted that the thundering sound of clouds was heard

6

seconds after the lightening was seen by him. If speed of sound in air is

340 m s^{- 1}

, find the distance of the point where the thundering sound was produced.

EASY

7th CBSE

IMPORTANT

The Living World A book of Science and Technology>Chapter 6 - Motion and Time>Something To Know>Q 3

How can we make a simple pendulum?

EASY

7th CBSE

IMPORTANT

The Living World A book of Science and Technology>Chapter 6 - Motion and Time>Something To Know>Q 3

A simple pendulum takes

10

seconds to complete

5

oscillations. Find the time period of this pendulum.

EASY

7th CBSE

IMPORTANT

The Living World A book of Science and Technology>Chapter 6 - Motion and Time>Something To Know>Q 4

Carefully examine the data given below for the motion of two different objects A and B. State whether the motion of these two objects is uniform or non-uniform.
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EASY

7th CBSE

IMPORTANT

The Living World A book of Science and Technology>Chapter 6 - Motion and Time>Something To Know>Q 5

Observe the graph given here. From the graph, find the values of distances 'P' and 'Q' in 'm'.

Question Image

EASY

7th CBSE

IMPORTANT

The Living World A book of Science and Technology>Chapter 6 - Motion and Time>Something To Know>Q 5

Observe the graph given here. From the graph, find the value of time 'R' in 'seconds.
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EASY

7th CBSE

IMPORTANT

The Living World A book of Science and Technology>Chapter 6 - Motion and Time>Value Based Question>Q 1

In the science class, Drishti observed a video showing the working of a pendulum wall clock. She noted that a slight change in the initial displacement of the (bob) did not affect the time-period of the pendulum. When she discussed her observation with her grandfather, he told her that we must also not let the effects of small disturbances to change the daily routine and the values of our life.
State any four values that we should maintain in our life.

Draw the shape of a distance-time graph for a man, walking on a level, straight and narrow road, at a constant speed.

Important Questions on Motion and Time

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