Calculating Average Speed for Wasim's Journey
To find the average speed for the whole journey, we need to calculate the total distance traveled and the total time taken.
The formula for average speed is:
$ \text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}} $Calculating Time for Each Segment
We calculate the time taken for each part of the journey using the formula $ \text{Time} = \frac{\text{Distance}}{\text{Speed}} $.
- Part 1: Distance = 455 km, Speed = 91 km/hr. $ t_1 = \frac{455 \text{ km}}{91 \text{ km/hr}} = 5 \text{ hours} $
- Part 2: Distance = 390 km, Speed = 78 km/hr. $ t_2 = \frac{390 \text{ km}}{78 \text{ km/hr}} = 5 \text{ hours} $
- Part 3: Distance = 476 km, Speed = 68 km/hr. $ t_3 = \frac{476 \text{ km}}{68 \text{ km/hr}} = 7 \text{ hours} $
Calculating Total Distance and Total Time
Now, we sum the distances and times from all segments.
- Total Distance: $ \text{Total Distance} = 455 \text{ km} + 390 \text{ km} + 476 \text{ km} = 1321 \text{ km} $
- Total Time: $ \text{Total Time} = t_1 + t_2 + t_3 = 5 \text{ hr} + 5 \text{ hr} + 7 \text{ hr} = 17 \text{ hours} $
Calculating Average Speed
Using the total distance and total time, we find the average speed.
$ \text{Average Speed} = \frac{1321 \text{ km}}{17 \text{ hours}} $Performing the division:
$ \text{Average Speed} \approx 77.70588... \text{ km/hr} $Rounding the Answer
The question asks to round the answer to two decimal places.
Rounded Average Speed = $77.71$ km/hr.
Similar Questions
- Heena covers a certain distance by train at 110 km/h and she returned to the starting point covering the same distance, driving a car at 50 km/h. Find her average speed for the whole journey.
- A man completes a journey in 11 h. He travels first half of the journey at the speed of 25 km/h and the second half at the speed of 30 km/h. Find the total distance of the journey.
- Sachin covers a certain distance by car driving at 80 km/h and he returns to the starting point riding on a scooter at 50 km/h. Find his average speed for the whole journey up to 2 decimal places.
- An aeroplane flies along the sides of an equilateral triangle at the speed of 300 km/h, 200 km/h and 240 km/h, respectively. The average speed of the plane while flying around the triangle is:
- If a motor car travels the first half of a distance at a speed of 30 km/h and the remaining half distance at a speed of 50 km/h, what will be its average speed?
- What is Ram's average speed if he goes from Point X to Point Y at 8 km/hr and returns from Point Y to Point X at 12 km/hr?
- A bus covers the first 50 km of its journey in 95 min and covers the remaining 70 km in 85 min. What is the average speed of the bus?
- A man rides his bicycle for 10 km at an average speed of 12 km/h and further travels 12 km at an average speed of 10 km/h. What is his approximate average speed for the entire trip?
- A person starting from his house covers a distance at 15 km/hr and returns to the starting place at a speed of 10 km/hr. His average speed during the whole journey is:
- A man completes 30 km of a journey at 6 km/hr and the remaining 40 km of the journey in 5 hr. His average speed for the whole journey is:
Important Questions from Average Speed
A car runs first 275 km at an average speed of 50 km/h and the next 315 km at an average speed of 70 km/h. What is the average speed ( in km/h) for the entire journey?
Akhil rides first 12 km at a speed of 16 km/h and further 6 km at a speed of 20 km/h. Find his average speed (in km/h).
Shyam drives his car 30 km at a speed of 45 km/h and, for the next 1 h 20 m, he drives it at a speed of 51 km/h. Find his average speed (in km/h) for the entire journey.
X and Y travel a distance of 90 km each such that the speed of Y is greater than that of X. The sum of their speeds is 100 km/h and the total time taken by both is 3 hours 45 minutes. The ratio of the speed of X to that of Y is:
If a man travels at \(\frac{1}{x}\) km/h on a journey and returns at \(\rm \frac{1}{x^2}\) km/h, then his average speed for the journey is:
