4.A man walks 7 km East in 2 hours and then 2.5 km toward West in 1 hour. Which of the following statements are true?
2 Marks
The man's average speed for the whole journey is 3km/hr
The man's average velocity for the whole journey is 1.5km/ hr
The man's average speed for the whole journey is 1.5km/hr
The man's average speed for the whole journey is 3.2km/hr
Answers
Step-by-step explanation:
We know that
Speed = Total distance / Total time
Total distance travelled by man = 7 km + 2 km = 9 km
Total time taken = 2 + 1 = 3 hrs
Average speed = 9/3 = 3 km/hour.
Velocity = Total displacement / Total time
Average velocity will be the same as average speed in this case since there is no direction change mentioned.
Therefore Total Displacement = Total Distance
average velocity = average speed = 3 km/hour.
Hence
Average speed = 3 km/hr.
Average velocity = 3 km/hr.
Answer:
(a) 3.1667km/hr (b) 1.5km/hr
Step-by-step explanation:
(a) Average speed= the total distance travelled / total time taken =(7+2.5km)/(2+1)hr =9.5/3km/hr =3.1667km/hr
(b) average velocity= displacement/ total time displacement is 7km-2.5km =4.5km ( he walked 2.5km in the opposite of his initial direction) the average velocity =4.5/(2+1) =4.5/3 =1.5km/hr