Science
Physics
Motion
Numericals
Kindly help in solving this question as I have my test tomorrow. Please

Dear Student,
Rehan accelerates from 6 m/s to 12 m/s in 30 sec.
Acceleration in this case is
$a=\frac{dv}{dt}=\frac{12-6}{30}=\frac{6}{30}=\frac{1}{5} m{s}^{-2}$
He then applies the brakes and comes to rest i.e. v=0 in 5 s. Since, the velocity decreases from 12 m/s to v=0 m/s, so Rehan decelerates i.e., acce.eration will be negative and is given as,
$a\text{'}=\frac{dv}{dt}=\frac{0-12}{5}=\frac{-12}{5}=-2.4 m{s}^{-2}$
Regards