Answer: Fa = 10N
Explanation: First use a fab 5 equation using the values given in the question. distance is irrelevant so use an equation without distance
Solve for acceleration.
vi = 3m/s
vf = 7m/s
t = 2s
a = ?
a = vf-vi/t
a = 7-3/2
a = 4 / 2
a = 2m/s^2
Then use Fa = ma (applied force = mass x acceleration) to solve for applied force
Fa = ma
Fa = (5)(2)
Fa = 10N
Therefore the applied force is 10N. Hope this helps!! :)