Question

A train first travels for 30min with a velocity 30km h-1and then for 40min with velocity 40km h-1 in the same direction finda)total distance travelled b)the average velocity of train

Answer 1

Given information :

Velocity of train ( ${v}_{1}$ ) = 30kmph

Time taken by train (${t}_{1}$) = 30min = $\frac{1}{2}$min

Velocity of train (${v}_{2}$) = 40kmph

Time taken by train (${t}_{2}$) = 40min = $\frac{2}{3}$min

As we know the distance formula

Distance = Speed × Time

According to the info., we got two velocities and two time

Distance = ${v}_{1}{t}_{1}+{v}_{2}{t}_{2}$

Distance = $(30*\frac{1}{2})+(40*\frac{2}{3}$

Distance = 15+26.6

Distance = 41.6km

Now we also need to find the average velocity.

$\bold{Avg. Velocity =\frac{Distance}{Total\:Time}}$

T.time = $\frac{1}{2}+\frac{2}{3}$

T.time = $\frac{7}{6}$

Avg. Velocity = $\bold{\frac{41.6}{\frac{7}{6}}}$

Avg. Velocity ≈ 36kmph