A car travels from position A to position B with a speed of 60 km/h and returns
from B to A with a speed of 40 km/h. Calculate average speed and average velocity
during entire journey?
Let x km distance between position A and position B.
Answers
Answer:
Answer: Average speed is 48 km/ hr
Average velocity is 0 km/ hr.
A to B journey: Let us say distance is x km.
Speed is 60 km/hr. Time= Dist./ Speed.
Time taken to travel from A to B = x/60 hr.
Now consider B to A journey:
Distance will remain the same = x km.
Speed = 40 km/ hr. Time= Dist./ Speed.
Time taken to travel from B to A= x/40 hr.
Now average speed = total dist. Covered/ total time required
Avg speed= (x+x)/ (x/60 + x/40)
Avg speed= 2x / (5x/120)
Avg speed = 2x * 120 / 5x
Avg speed = 48 km/ hr.
Now if we consider the velocity, which is a vector quantity, we should consider the total displacement to the total time. Since it is journey from A to B & then returned back from B to A, resultant (or net) displacement is zero. So average velocity is also 0 km/hr.
Sanjay C.
Answer:
Average speed is 48 km/ hr
Average velocity is 0 km/ hr.
A to B journey: Let us say distance is x km.
Speed is 60 km/hr. Time= Dist./ Speed.
Time taken to travel from A to B = x/60 hr.
Now consider B to A journey:
Distance will remain the same = x km.
Speed = 40 km/ hr. Time= Dist./ Speed.
Time taken to travel from B to A= x/40 hr.
Now average speed = total dist. Covered/ total time required
Avg speed= (x+x)/ (x/60 + x/40)
Avg speed= 2x / (5x/120)
Avg speed = 2x * 120 / 5x
Avg speed = 48 km/ hr.
Now if we consider the velocity, which is a vector quantity, we should consider the total displacement to the total time. Since it is journey from A to B & then returned back from B to A, resultant (or net) displacement is zero. So average velocity is also 0 km/hr.