The question given seems to be incomplete, however (f) refers to the focal point at which the image is standing in order for it to be mirrored by a converging or a diverging lens. The statement above is correct that converging lens create positive focal images, and diverging lenses create negative focal images.
<h3><u>Mass of an object affect the outcome of unbalanced forces:</u></h3>
Newton’s second law of motion deals with the result of motion of an object when unbalanced forces are applied. The second law of motion establish the relationship between mass, acceleration and unbalanced forces of the object. The below points explains the relation between unbalanced forces acting on mass of the object. The acceleration of object would be higher when the unbalanced force is higher.
The equation for the unbalanced force is,
For Example: Two masses of 500 kg and 1 kg is applied with same unbalanced forces. The change in motion of 500 kg would be very much less than the change in motion of 1 kg.