Answer:
18N
Step-by-step explanation:
According to Newtons second law
F ∝ a
F = ka
k is the constant of proportionality
When a force of 8 N acts on a certain object, the acceleration of the object is 4 m/s2, hence;
8 = 4k
k = 8/4
k = 2
If a = 9m/s², F = ?
Recall F = ka
F = 2 * 9
F = 18N
Hence the force will be 18N