Question

1. A car travels from town A to town B that is 150 km away in 3 hours and from town B to town
C which is 120 km away in 2 hours. Find the average speed of the car.
Al​

Answer 1

Answer:

E

Distance travelled by car in 3 hours=150 km

Distance travelled by car in 2 hours=120 km

We know that the average speed of the particle is defined as the total distance covered per unit time

According to question

Let v be the average speed of the particle given by

Hence the average speed of the car is calculated

Answer 2

Given:

A car travels from town A to town B that is 150 km away in 3 hours

Also the car travels from town B to town  C which is 120 km away in 2 hours

To Find:

Average speed of the car

Solution:

We know that,

• $\pink{\boxed{\bf{Time=\frac{Distance}{Speed}}}}$

Average speed of body S is given by

• $\purple{\boxed{\bf{S=\frac{Total\:distance\:covered}{Total\:time\:taken}}}}$

$\rule{190}{1}$

Let the time taken by car to travel from town A to town B be t₁ and the time taken by car to travel from town B to town C be t₂

$\rule{190}{1}$

Let the average speed of car be S

So,

$\longrightarrow\rm{S=\dfrac{Total\:distance\:covered\:by\:car}{Total\:time\:taken\:by\:car}}$

$\longrightarrow\rm{S=\dfrac{150+120}{t_{1}+t_{2}}}$

$\longrightarrow\rm{S=\dfrac{270}{3+2}}$

$\longrightarrow\rm{S=\dfrac{270}{5}}$

$\longrightarrow\rm\green{S=54\:km/h}$

Hence, the average speed of the car for the given journey is 54 km/h.