Question

a rightward force is applied to a 36 kg object to accelerate it to the right at 8.3 m/s/s. the friction force between the object and the surface is 55 n.

(force diagram with f_norm upward, f_frict left, f_app right, f_grav downward)

units
force: n
mass: kg
acceln: m/s/s
m =
a =
f_net =

(other text below about action - reaction forces and atom questions, but focusing on the force problem above)

Explanation:

Step1: List given values

$m=36\ \text{kg}$, $a=8.3\ \text{m/s}^2$, $F_{frict}=55\ \text{N}$, $g=9.8\ \text{m/s}^2$

Step2: Calculate gravitational force

$F_{grav}=m \times g = 36\ \text{kg} \times 9.8\ \text{m/s}^2 = 352.8\ \text{N}$

Step3: Find normal force

$F_{norm}=F_{grav}=352.8\ \text{N}$

Step4: Calculate net force

$F_{net}=m \times a = 36\ \text{kg} \times 8.3\ \text{m/s}^2 = 298.8\ \text{N}$

Step5: Solve for applied force

$F_{app}=F_{net}+F_{frict}=298.8\ \text{N}+55\ \text{N}=353.8\ \text{N}$

Answer:

$F_{frict}=55\ \text{N}$
$F_{grav}=352.8\ \text{N}$
$F_{norm}=352.8\ \text{N}$
$F_{app}=353.8\ \text{N}$
$m=36\ \text{kg}$
$a=8.3\ \text{m/s}^2$
$F_{net}=298.8\ \text{N}$