Question

A train travells at a speed of 60km/ hour next point0.24hour
for 30km/hour. next hour70km/hour for 0.71​

Answer 1

Answer:

Given :-

First speed, v₁ = 60 km/h

Time taken for this part of trip, t₁ = 0.52 h

Second speed, v₂ = 30 km/h

Time taken for this part of trip, t₂ = 0.24 h

Third speed, v₃ = 70 km/h

Time taken for this part of trip, t₃ = 0.71 h

To Calculate :-

Average speed, V(avg) = ???

Formula to be used :-

Distance = Speed × Time

V(avg) = Total distance/Total time taken

Solution :-

Now, in this case we are not given the total distance traveled. so first of all we will find out the distance covered during the three given intervals by using the formula,

Distance = Speed × Time

(i) 1st part, d₁ = v₁ × t₁ = 60 × 0.52 = 156/5 km

(ii) 2nd part, d₂ = v₂ × t₂ = 30 × 0.24 = 36/5 km

(iii) 3rd part, d₃ = v₃ × t₃ = 70 × 0.71 = 497/10 km

Total distance, d = d₁ + d₂ + d₃

= 156/5 + 36/5 + 497/10 = 881/10 = 88.1 km

Total time taken, t = t₁ + t₂ + t₃

= 0.52 + 0.24 + 0.71 = 1.47 h

Now,

V(avg) = Total distance/Total time taken

⇒ V(avg) = 88.1/1.47

⇒ V(avg) = 59.93 km/h.

Hence, the average speed of the train is 59.93 km/h.