Question

Over a period of 15s,a plane changes it's velocity from 250kmph to 150kmph at a uniform rate of acceleration.How far does the plane travel during this amount of time?
Please help me..

Answer 1

$\huge{\underline{\green {\sf {Answer:}}}}$

$\underline {\bold{\pink {Given:}}}$

➣$u=250 \ km/h = 69.44 \ m/s$

➣$v = 150\ km/h = 41.67\ m/s$

➣$t = 15 \ s$

➣$s = ? \ (to \ be \ found)$

$\underline{\bold{\pink{Solution:}}}$

✮By formula :

$\boxed{a = \dfrac{v-u}{t}}$

✦Putting values :

➫$a = \dfrac{41.67 - 69.44}{15}$

➫$a = \dfrac{-27.77}{15}$

➫$\red{\boxed{\implies{\boxed{a = -1.85 \ m/s^2}}}}$

✮By formula :

$\boxed{s = \dfrac{v^2 - u^2 }{2a}}$

✦Putting values :

➫$s = \dfrac{(41.67)^2 - (69.44)^2}{2 \times -1.85}$

➫$s = \dfrac{1736.38 - 4821.91}{-3.7}$

➫$s = \dfrac{-3,085.53}{-3.7}$

$\blue{\boxed{\implies{\boxed{s=833.93 \ m}}}}$

______________________________________