A rubber band is tied between two fixed hooks P and Q on a horizontal line apart
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A rubber band is tied between two fixed hooks P and Q on a horizontal line 0.40m apart. Student X pulls the middle point of the rubber band to the right with a horizontal force of 15N while student Y simultaneously pulls the same point to the left with a horizontal force of 12N.
(i) Draw an arrow diagram to represent the two forces FX and FY acting on the rubber band at that instant.
(ii) Determine the magnitude and direction of the net force acting on the rubber band.
(iii) State with reasons whether, at that instant, the rubber band will (a) move to one side, (b) change its length, or (c) both.
(iv) After a while student Y adjusts his pull so that the rubber band stays stretched but its middle point no longer moves. What must be the magnitude of Y’s pull now? Explain how the forces acting on the rubber band are related in this condition.