Compare how lateral inversion happens in a plane mirror and a concave mirror

If the force on an object is in the negative direction, the work it does on the object must be [2 points a) negative. b) positive c) the work could be either positive or negative, depending on the direction the object moves

In an experiment, how can i change human errors? be specific.

In which of the following is positive work done by a person on a suitcase