Question

A particle travels half the distance at 12km/hr and the remaining half at 18km/hr. Calculate the average speed

Answer 1

Given :

✪ Particle travels first half of the total distance at a speed of 12kmph and second half of the totak distance at a speed of 18kmph.

To Find :

⎆ Average speed of particle.

ConcepT :

➛ Average speed is defined as the ratio of total distance travelled to the total time taken.

➛ It is a scalar quantity.

➛ It has only magniude

➛ It can't be negative or zero.

➛ SI unit : m/s

⇒ If body covers first half of the total distance at a speed of V¹ and second half of the total distance at a speed of V² then average apeed of body is given by

✭ Vav = 2V¹V²/(V¹+V²)

CalculaTion :

➠ Vav = 2V¹V²/(V¹+V²)

➠ Vav = 2×12×18/(12+18)

➠ Vav = 432/30

➠ Vav = 14.4 kmph

Answer 2

$\huge\sf\pink{Answer}$

☞ Average Speed = 14.4 km/h

$\rule{110}1$

$\huge\sf\blue{Given}$

✭ $\sf Speed_1 = 12 km/h$

✭ $\sf Speed_2 = 18 km/h$

$\rule{110}1$

$\huge\sf\gray{To \:Find}$

◈ The Average speed?

$\rule{110}1$

$\huge\sf\purple{Steps}$

We know that,

$\underline{\boxed{\sf V_{Av} = \dfrac{2V_1 V2}{V_1+V_2}}}$

➝ $\sf V_{Av} = \dfrac{2 \times 12 \times 18}{12+18}$

➝ $\sf V_{Av} = \dfrac{432}{30}$

➝ $\sf\orange{V_{Av} = 14.4 km/h}$

$\rule{170}3$