Question

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

Answer 1

15 N

Explanation:

The relationship between force, mass and acceleration of an object is given by Newton's second law of motion:

`F=ma`

where:

F is the force

m is the mass

a is the acceleration

For the object in this problem, at the beginning we have

F = 18 N

`a=6 m/s^2`

So, the mass of the object is

`m=(F)/(a)=(18)/(6)=3 kg`

Later, we are told that the acceleration of the object becomes

`a=5 m/s^2`

And the mass of the object is still the same, therefore the new force exerted on the object is:

`F=ma=(3)(5)=15 N`