Question

A BOY UNDER 10KM EAST IN 2 HRS AND THEN 2.5 KM WEST IN 1 HR. CALCULATE THE TOTAL AVERAGE VELOCITY OF THIS BOY

Answer 1

Answer:

2.5 km/hr

Explanation:

Given:

Displacement towards east = 10 km

Time for travelling 10 km towards east = 2 hrs

Displacement towards west = 2.5 km

Time for travelling 2.5 km west = 1 hour

To find:

Average velocity of the body

$Average\ velocity=\frac{total\ displacement}{total\ time}$

As the boy is travelling towards east and then west , the distance travelled towards west should be subtracted from the distance travelled towards east

Total displacement = 10km-2.5km

Total displacement = 7.5 km

Total time = 1 hour+2hours

Total time = 3 hours

$average\ velocity=\frac{7.5}{3}$

$average\ velocity = 2.5 km/hr$

The average velocity is equal to 2.5 km/hr

Answer 2

Answer:

$\bigstar\:\boxed{\sf Average\: Velocity=\dfrac{Total\: Displacement}{Total\:Time}}$

$\rule{120}{1}$

• Boy travelled 10km East in 2 hours & Then 2.5km West in 1 hour.
• As Boy Returned towards East, therefore according to Definition : Distance from Starting Point to End Point is Displacement.

$\underline{\bigstar\:\textbf{According to the Question :}}$

$:\implies\sf Average\: Velocity=\dfrac{Total\: Displacement}{Total\:Time}\\\\\\:\implies\sf Average\: Velocity=\dfrac{10-2.5}{2+1}\\\\\\:\implies\sf Average\: Velocity=\dfrac{7.5}{3}\\\\\\:\implies\underline{\boxed{\sf Average\: Velocity=2.5\:km/hr}}$

⠀

$\therefore\:\underline{\textsf{Average Velocity of Boy will be \textbf{2.5 km/hr}}}.$