If p = 100 n, m = 45 kg, and theta = 25 degrees, what are the magnitudes for the following forces?
a) the frictional force acting upon the box?

Friction force is the resisting force acting on an object that prevents the object to move upwards or slide downwards.In this experiment the object is restrained from moving because of  forces of gravity and its own weight.in this case, friction is equal to the weight of the object multiplied by the cosine of the theta(angle at which the object is ) 45*cos 25=44.6041 N

Is a  vector quantity  that refers to "the rate at which an object changes its position." imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. while this might result in a frenzy of activity, it would result in a zero velocity. because the person always returns to the original position, the motion would never result in a change in position. since velocity is defined as the rate at which the position changes, this motion results in zero velocity. if a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. every step must go into moving that person further from where he or she started. for certain, the person should never change directions and begin to return to the starting position.