Part a a box is being pulled to the right over a rough surface. t > fk , so the box is speeding up. suddenly the rope breaks. what happens? the box a box is being pulled to the right over a rough surface. t > , so the box is speeding up. suddenly the rope breaks. what happens? the box keeps its speed for a short while, then slows and stops. slows steadily until it stops. stops immediately. continues speeding up for a short while, then slows and stops. continues with the speed it had when the rope broke.