Do psychopaths catch the contagiousness of yawning

A50.0-n box is sliding on a rough horizontal floor, and the only horizontal force acting on it is friction. you observe that at one instant the box is sliding to the right at and that it stops in 2.25 s with uniform acceleration. what magnitude force does friction exert on this box

You and a friend (alex) are at a a tree-top adventure park .. . part of the course requires you to climb up a rope. you both climb the same rope in the same amount of time. however, the tension in the rope is greater when alex climbs. who did the most work? alex did - more tension means more force - more force means more work was done you did - less tension means less force - less force means more work was done to find the work done, the force exerted and distance moved are multiplied. a couch is moved twice before you are happy with its placement. the same force was used to move the couch both times. if more work is done the first time it is moved, what do you know about the distance it was moved? when more work was done, the couch was moved less. when more work was done, the couch was moved further. when more work was done, the couch wasn't moved at all. when more work was done, the couch was moved the same distance.

Find v(t), given acceleration a(t)=7j and initial velocity v(0)=k