Question

A train has speed 60 km/h for the first 1 hour & 40 km/h for for next 1/2 hour.Find average speed.

Answer 1

Heya........!!!!


We know that Average Speed = Total distance/total time

So ,, we need Total time ( T )

=> T = t1 + t2 = 1 + 1/2 = 3/2

Total Distance ( D )

=> D = d1 + d2 ,,
d1 = v1 × t1 = 60 × 1 = 60 Km

d2 = v2 × t2 = 40 × 1/2 = 20 Km

D = 80 Km
T = 3/2 h

Average Speed = D/T = 80 ÷ 3/2

=> 160÷ 3

➡➡ Average Speed = 53 .33 Km/h



Hope It Helps You ☺

Answer 2

Hi there !!
Here your answer !

Given,

Speed of train in(v1) = 60km/hr
Time taken= 1 hour

v2 = 40km/hr
Time = 1/2

We know,

$average \: speed \: = \frac{total \: distance}{total \: time}$


Total distance (s) { distance = speed × time}

s1 = 60km/hr × 1 hr = 60km

$s2 = 40kmhr { }^{ - 1} \times \frac{1}{2} hr$
s2 = 20km

Total distance = 60km + 20km = 80km


Total time (t)
$= 1 + \frac{1}{2} = \frac{3}{2} hrs$

Using the formula to find average speed,

we have,

$average \: speed \: = \frac{80km}{ \frac{3}{2}hr }$


$= \frac{80}{3} \times 2 \: kmhr {}^{ - 1}$

= 160/3 km/hr

= 53.333.. km/hr

Thus,
the average speed is 53.333 km/hr