NCERT Class 11 Physics Solutions: Chapter 3 – Motion in a Straight Line Part 2

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Question: 3.3

A woman starts from her home at 9.00 am, walks with a speed of 5 km on a straight road up to her office 2.5 km away, stays at the office up to 5.00 pm, and returns home by an auto with a speed of 25 km Choose suitable scales and plot the graph of her motion.

Answer:

  • Speed of the woman

  • Distance between her office and home

Time taken

  • It is given that she covers the same distance in the evening by an auto.

  • Now, speed of the auto

Time taken

  • The suitable graph of the motion of the woman is shown in the given figure.

Shows the time v/s distance in image

Graph Shows the Time V/S Distance

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Question: 3.4

A drunkard walking in a narrow lane taken 5 steps forward and 3 steps backward, followed again by 5 steps forward and 3 steps backward, and so on. Each step is 1 m long and requires 1 s. Plot the graph of his motion. Determine graphically and otherwise how long the drunkard takes to fall in a pit 13 m away from the start.

Answer:

  • Distance covered with a step

  • Time taken

  • Time taken to move first 5 m forward

  • Time taken to move 3 m backward

  • Net distance covered

  • Net time taken to cover

  • Drunkard covers in. Drunkard covered in. Drunkard covered in. Drunkard covered 8 m in 32 s.

  • In the next, the drunkard will cover a distance of and a total distance of and falls into the pit.

  • Net time taken by the drunkard to cover

  • The graph of the drunkard’s motion can be shown as:

Showing the time v/s distance in graph

Showing the Time V/S Distance in Graph

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