# An object with a mass of 7 kg is on a surface with a kinetic friction coefficient of  7 . How much force is necessary to accelerate the object horizontally at 2 m/s^2?

Mar 14, 2016

$F = 494 , 69 \text{ } N$

#### Explanation:

$G = m \cdot g = 7 \cdot 9 , 81 = 68 , 67 N \text{ gravity of object}$
$N = - G \text{ normal force to the contacting surfaces}$
${F}_{f} = k \cdot N = 7 \cdot 68 , 67 = 480 , 69 N$
$\text{The friction force for contacting surfaces}$
${F}_{\text{net"=m*a" The Newton's second law}}$
${F}_{\text{net}} = F - {F}_{f}$
$F - {F}_{f} = m \cdot a$
$F - 480 , 69 = 7 \cdot 2$
$F - 480 , 69 = 14$
$F = 480 , 69 + 14$
$F = 494 , 69 \text{ } N$