# A body of mass $4 kg$ is at rest on a horizontal table. The coefficient of friction between body and table is 0.3 . Find the acceleration of the body if a horizontal force applied on the body is 20 N

$(a)\;2.06 m/s^2 \quad (b)\;2.6 m/s^2 \quad (c)\;1.82 m/s^2 \quad(d)\;1.06 m/s^2$

$R=mg$
$\quad=4 \times 9.8$
$\quad=39.2 N$
Therefore $f=\mu mg$
$\quad \qquad= 0.3 \times 39.2N$
$\quad\qquad=11.76 N$
$F-f\; =ma$
$20-11.76=4a$
$\qquad \quad 8.24=4a$
$\qquad\qquad a= 2.06 m/s^2$
Hence a is the correct answer.

edited Jan 26, 2014 by meena.p