Answer:
F = 7.7 [N]
Step-by-step explanation:
In order to solve this problem, we must use Newton's second law, which tells us that the sum of forces on a body is equal to the product of mass by acceleration.
ΣF = m*a
where:
m = mass = 3.5 [kg]
a = acceleration = 2.2 [m/s^2]
F = (3.5*2.2) = 7.7 [N]