There are generally two ends of a hammer. By one end drive a nail into wood and by another end it plucks nail out of wood. When nails are plucked by hammer force is applied by holding the hammer’s handle by the hand. Again a nail is plucked by pressing the hammer against the area surrounding the nail, which functions as fulcrum. In this ease the resistance against pulling out of the nail functions as weight. Here as the fulcrum works in the middle, it functions as a class I lever.
Forceps also act as a lever. The end where the hand holds the forceps is the force end and the end where the substance is grasped acts as the weight or load. Here, the pivot remains at the middle, so forceps is included in class-I lever. In it the length of the load-arm is unchangeable, so the mechanical advantage is availed only by changing the length of the force-arm.