Question

An object travels with 20m/sec for 5 sec and 30m/sec for next 10 sec.Calculate the average speed of object in 15 sec?

Answer 1

Answer:

Avg speed=Total distance/Total Time

Total d=20×5+30×10=400m

Total time=15sec

Avg speed=400/15=26.6m/s

Answer 2

$\sf{\huge{\mathfrak{\pink{\underline{Question}}}}}$

• An object travels with 20m/sec for 5 sec and 30m/sec for next 10 sec.Calculate the average speed of object in 15 sec?

$\sf{\mathfrak{\huge{\pink{\underline{Solution}}}}}$

$\sf{\bold{\green{\underline{\underline{1st \:observation}}}}}$

speed = 20m/s

time = 5sec

$\sf{\bold{\red{\boxed{speed = \dfrac{distance}{time}}}}}$

$20 = \dfrac{distance}{5sec}$

$distance = 20 \times 5$

$distance = 100 meter$

$\sf{\bold{\green{\underline{\underline{2nd\: observation}}}}}$

speed = 30m/s

time = 10sec

$\sf{\bold{\red{\boxed{speed = \dfrac{distance}{time}}}}}$

$30 = \dfrac{distance}{10 sec}$

$distance = 30 \times 10$

$distance = 300 meter$

$\sf{\bold{\red{\boxed{average\:speed = \dfrac{total\:distance\:travelled}{Total\:time\:taken}}}}}$

$average \: speed = \dfrac{ 300 + 100 }{ 5 + 10 }$

$average \: speed = \dfrac{\cancel{400}}{\cancel{15}}$

$average \: speed = \dfrac{80}{3}$

$average \: speed = 26.666m/sec$

$\sf{\bold{\purple{\boxed{\dag average \: speed = 26.67m/sec}}}}$

_________________❤