In the following situations identify the agent exerting the force and the object on which it acts. State the effect of the force in each case. (a) Squeezing a piece of lemon between the fingers to extract its juice. (b) Taking out paste from a toothpaste tube. (c) A load suspended from a spring while its other end is on a hook fixed to a wall. (d) An athlete making a high jump to clear the bar at a certain height.

(a) In squeezing a piece of lemon, the force responsible is muscular force which changes the shape of the lemon, and the agent exerting the force is the fingers. (b) In taking out paste from a tube, the force changes the shape of the tube, and the agent exerting the force is the hands or fingers. (c) In suspending a load from a spring while the other end is on a hook fixed, the force changes the shape of the spring, and the agent exerting the force is the load. (d) In the high jump by the athlete, the force acts on the ground, and the ground helps the athlete in jumping. The effect is a change in motion, and the cause is muscular force or friction force.