Question

For a moving object, the force acting on the object varies directly with the object's acceleration. When a force of 15 N acts on a certain object, the acceleration of the object is 5 /ms2. If the acceleration of the object becomes 9 /ms2, what is the force?

Answer 1

27 N

Explanation:

Since force varies directly with acceleration, we can introduce a constant, k, and write
`F=ka`

When force is 15, acceleration is 5, so plug it into the equation and solve for k:

`F=ka\\15=k(5)\\k=(15)/(5)\\k=3`

Now, to find force, we use a = 9 and k = 3, so

`F=ka\\F=(3)(9)\\F=27`

The force is 27 N