Question

A car starting from a speed of 12 m/s slows to 6 m/s in a time of 3 s. Calculate the average acceleration of the car?
[Unless otherwise mention, use $g=10m/s^2$ and neglect air resistance ]

• A. $2m/s^2$
• B. $4m/s^2$
• C. $3m/s^2$
• D. $-2m/s^2$
• E. $-4m/s^2$

Answer 1

The correct option is D $-2m/s^2$

Given : $u=12$ m/s $v=6$ m/s $t=3$ s

Using $v=u+at$

$\therefore$ $6=12+a\times 3$ $⟹a=-2$ $m/s^2$