IN THE 8th STD SCIENCE BOOK, IN THE THIRD CHAPTER (ATMOSPHERIC PRESSURE) I HAVE A DOUBGHT.IN THE FIRST EXPERIMENT OF TRY THIS ,THE EQUATION (WHEN THE FORCE IS APPLIED TO AN OBJECT , THE EFFORT PRODUCED BY THE OBJECT DEPENDS UPON THE AREA OF THE SURFACE ON WHICH THE FORCE IS ACTING)MAYBE WRONG , BECAUSE,THE EFFECT PRODUCED BY THE OBJECT ALSO DEPENDS UPON THE WEIGHT OF THE OBJECT. WHEN THE BRICK IS PLACED HORIZONTALLY, THE WEIGHT OF THE BRICK DISTRIBUTES TO A LARGER AREA.WHEREAS WHEN THE BRICK IS PLACED VERTICALLY ALLTHE WEIGHT OF THE BRICK CONCENTRATES IN ONLY A SHORT AREA , SO...... THE MARK ON THE MUD IS DEEPER THAN WHEN THE BRICK PLACED HORIZONTALLY