Forces that result in acceleration are unbalanced forces. An unbalanced force is a net force that is not equal to zero. When a net force is applied to an object, it causes the object to accelerate. The acceleration of an object is directly proportional to the net force applied to the object and inversely proportional to the mass of the object. The formula for acceleration is:

```

a = F / m

```

Where:

* a is acceleration

* F is net force

* m is mass