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.
1) Squeezing a piece of lemon brtween the fingers to extract its juice.
2) Taking out paste from a toothpaste tube.
3) A load suspended from a spring while its other end is on a hook fixed to a wall.
4) An athlete making a high jump to clear the bar at a certain height.