A car completes its journey in a straight line in three equal parts with speed v 3v and 5v .The average speed of car is
a.45v upon 23
b.90v upon 23
c.45v upon 46
d.3v
plzz ans fast it is of 10 point
Answers
Answer:
- Average speed of Car = 45v / 23
Correct option is (a)
Explanation:
Let, the total distance to be covered by 3 x
then,
Car will travel first x distance with velocity v ; next x distance with velocity 3 v ; and last x distance with velocity 5 v
So, using formula ; time = distance / speed
Calculating time taken by Car ( t₁ , t₂ , t₃ ) to cover these three intervals
→ t₁ = x / v
→ t₂ = x / (3 v)
→ t₃ = x / (5 v)
hence,
total time taken for the journey would be
→ t = t₁ + t₂ + t₃
→ t = ( x / v ) + ( x / (3 v) ) + ( x / (5 v) )
→ t = ( 15 x + 5 x + 3 x ) / ( 15 v )
→ t = ( 23 x ) / ( 15 v )
Now,
Using formula
Average speed = total distance covered / total time taken
→ Average speed = ( 3 x ) / ( (23 x) / (15 v) )
→ Average speed = ( 3 x ) ( 15 v ) / ( 23 x )
→ Average speed = (45 v) / 23
Therefore,
- Average speed of the Car would be 45 v / 23 .
OPTION (a) is correct.
Answer:
45v/23 is the correct option.