Joseph jogs from one A to the other end B of a straight 300 m road in 2
minutes 50 seconds and then turns around and jogs 100 m back to point
C in another 1 minute. What are Joseph's average speeds and velocities
in jogging(a) from A to B and (b) from A to C?
Answers
⋆ Correct question: Joseph jogs from one A to the other end B of a straight 300 m road in 2 minutes 50 seconds and then turns around and jogs 100 m back to point C in another 1 minute. What are Joseph's average speeds and velocities in jogging (a) from A to B and (b) from A to C?
⋆ Joseph jogs from one A to the other end B of a straight 300 m road in 2 minutes 50 seconds.
⋆ Then he turns around and jogs 100 m back to point C in another 1 minute.
⋆ Average speeds
- From A to B
- From A to C
⋆ Average velocities
- From A to B
- From A to C
⋆ Average speeds
- From A to B = 1.76 m/s
- From A to C = 1.73 m/s
⋆ Average velocities
- From A to B = 1.76 m/s
- From A to C = 0.86 m/s
⋆ 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
~ Firstly let us convert minutes into seconds in the both cases
Case 1st
→ 2 minutes 50 seconds
→ 2 × 60 + 50
→ 120 + 50
→ 170 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
→ 300/170
→ Average speed = 1.76 m/s
Average velocity 2nd
→ Total displacement/Total time
- Displacement is the shortest distance, here shortest distance is 300 metres itself.
→ 300/170
→ Average velocity = 1.76 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, 170 + 60 = 230 seconds
→ Total distance/Total time
→ 400/230
→ Average speed = 1.73 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.
→ 200/230
→ Average velocity = 0.86 m/s