Question

For a moving object, the force acting on the object varies directly with the object's acceleration. When a force of 18 N acts on a certain object, the acceleration of the object is 6 /ms2 . If the acceleration of the object becomes 5 /ms2 , what is the force?

Answer 1

Answer: $F=15N$

Step-by-step explanation:

1. You know that the force acting on the object varies directly with the object's acceleration. Then, by definition, you have:

$F=ka$

Where $F$ is the force acting on the object, $a$ is the object's acceleration and $k$ is the constant of proportionality.

2. Keeping this on mind, you can calculate the constant of proportionality by substituting $F=18$ and $a=6$ into the equation and solving for $k$:

$18=k6\\k=\frac{18}{6}\\k=3$

3. Now, you can calculate the force when the acceleration of the object becomes 5 m/s², as following:

$F=3(5)\\F=15$

3. The result is:

$F=15N$