Answer

Verified

435.9k+ views

**Hint:**The average speed of the train is given by the total distance travelled by train divided by the total time taken by it to travel that distance. We have to find the distance travelled in various time periods and then calculate the average speed by the before mentioned formula.

**Complete step by step answer:**

Average speed is actually the speed that an object needs to travel at so as to cover the same total distance in the same time that it did at different speeds for different time periods.

We have to calculate the total distance travelled by train in various time periods.

In the first case, the train travels at a speed of 60 km/h for 0.52hr

Now, speed = distance/time=60km/h

Distance= $60 \times 0.52 = 31.2km$

In the second case, the train travels at a speed of 30km/h for 0.24hr

Distance= $30 \times 0.24 = 7.2km$

In the third case, the train travels at a speed of 70km/h for a time of 0.71 hr, so

Distance= $70 \times 0.71 = 49.7km$

Now, we get the total distance travelled as,

$\Rightarrow 31.2 + 7.2 + 49.7 = 88.1km$

Also, we can get the total of travel as

$\Rightarrow0.52 + 0.24 + 0.71 = 1.47hr$

So, the average speed can be calculated now as,

Average speed = Total distance travelled / Total time taken

$\therefore v = \dfrac{{88.1km}}{{1.47hr}} = 59.9km/hr$

**Therefore, the correct answer is option D.**

**Note:**The units can also be converted to m/s and solved, that is however the options demand. Here, because all the options are in km/h , we needn’t convert the units. Also, we have to note that the average speed isn’t simply the average of all speeds, which is a common mistake made by students.

Recently Updated Pages

what is the correct chronological order of the following class 10 social science CBSE

Which of the following was not the actual cause for class 10 social science CBSE

Which of the following statements is not correct A class 10 social science CBSE

Which of the following leaders was not present in the class 10 social science CBSE

Garampani Sanctuary is located at A Diphu Assam B Gangtok class 10 social science CBSE

Which one of the following places is not covered by class 10 social science CBSE

Trending doubts

Which are the Top 10 Largest Countries of the World?

How do you graph the function fx 4x class 9 maths CBSE

The Equation xxx + 2 is Satisfied when x is Equal to Class 10 Maths

Fill the blanks with the suitable prepositions 1 The class 9 english CBSE

In Indian rupees 1 trillion is equal to how many c class 8 maths CBSE

Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE

One Metric ton is equal to kg A 10000 B 1000 C 100 class 11 physics CBSE

Why is there a time difference of about 5 hours between class 10 social science CBSE

Give 10 examples for herbs , shrubs , climbers , creepers