Answer Happy

Question 1 [25 marks] Assume that you own a luxury sporting car with gullwing doors, as shown in the figure below. Unfortunately, you drive the car into a lake. Water is accumulating in the car, so you need to open the door manually to escape. The door is unlocked now, so it can freely rotate regarding a hinge on top of the door. For simplicity, the cross section of the car is approximated by a trapezoidal shape. The door's width (in the direction perpendicular to the cross section) is 1.2 m. As sketched in the figure, the doors are sloped at an angle of 9=30° from vertical. The water depth at the top of the car is hi=im, and the depth of the car's interior is ha=1.4m. The water depth in the car is h. You can assume that the air pressure inside that car remains at the atmospheric pressure if h<h2. (a) What is the magnitude of the hydrostatic force acting on the outside of the door? [6 marks] (6) For h=0.4m, determine magnitude of the hydrostatic force from the inside. [5 marks] () To open the door, you need to create an opening moment Mo regarding the hinge on the door. Determine an expression of Mo as a function of h. [10 marks) (d) Assume that the maximum Mo you can produce is 4000 [N-m), discuss how you can escape from the car. [4 marks] K h EL Hinge open water h, h air water h