8.- What is the minimum force which we have to exert to open the door of a car which has had an accident and is submerged in the sea at a depth of 5 m? Data: The surface area of the door is 1 m2 and the density of sea water is 1030 kg/m3.

NB. To see the solutions drag the mouse over the "solutions" control. Try to solve it before clicking on "Answer" and then click and check your result.