Question

EXAMPLE 8 Abhay jogs from one end A to the other
end B of a straight 300 m road in 2 min 30 s and then
turns around and jogs 100 m back to point in another
1 min. What are Abhay's average speeds and velocities
in jogging a. from A to B and b. from A to C?​

Answer 1

⋆ Correct question: Abhay jogs from one A to the other end B of a straight 300 m road in 2 minutes 30 seconds and then turns around and jogs 100 m back to point C in another 1 minute. What are Abhay's average speeds and velocities in jogging (a) from A to B and (b) from A to C?

ProvidEd that:

⋆ Joseph jogs from one A to the other end B of a straight 300 m road in 2 minutes 30 seconds.

⋆ Then he turns around and jogs 100 m back to point C in another 1 minute.

To calculaTe:

⋆ Average speeds

• From A to B
• From A to C

⋆ Average velocities

• From A to B
• From A to

SoluTion:

⋆ Average speeds

• From A to B = 2 m/s
• From A to C = 1.90 m/s

⋆ Average velocities

• From A to B = 2 m/s
• From A to C = 0.95 m/s

Using concEpts:

⋆ Average speed is given by

• Total distance/Total time

⋆ Average velocity is given by

• Total displacement/Total time

⋆ 1 minute converted into seconds by

• 1 minute = 60 seconds

Full solution:

~ Firstly let us convert minutes into seconds in the both cases

Case 1st

→ 2 minutes 30 seconds

→ 2 × 60 + 30

→ 120 + 30

→ 150 seconds

Case 2nd

→ 1 minute

→ 1 × 60

→ 60 seconds

~ Now let us find out the average speed and average velocity in case 1st

Average speed 1st

→ Total distance/Total time

→ 300/150

→ Average speed = 2 m/s

Average velocity 2nd

→ Total displacement/Total time

Displacement is the shortest distance, here shortest distance is 300 metres itself.

→ 300/150

→ Average velocity = 2 m/s

~ Now let's find out the average speed and average velocity in case 2nd

Average speed 1st

Here, the total distance be AB + BC therefore, 300 + 100 = 400 metres.

Here the total time be AB + BC therefore, 150 + 60 = 210 seconds

→ Total distance/Total time

→ 400/210

→ Average speed = 1.90 m/s

Average velocity 2nd

→ Total displacement/Total time

Displacement is the shortest distance, here shortest distance is AB - BC that is 300 - 100 = 200 metres.

→ 200/210

→ Average velocity = 0.95 m/s $\:$