The photo shows a pair of scissors showing the application of a Class 1 lever.When a force is applied to close one end of the scissors the other end will also close.
The photo shows the application of a worm gear.When the worm gear is turned,the toothed piece connected to it will move up or down.
The photos show linkages,a Class 2 lever and an inclined plane.When the tool is in the "open" position we can clearly see the 4 linked pieces that enable the tool to close and open.The Class 2 lever helps the tool to open after it is closed,with the fulcrum at one end,the load in the middle and the effort at the end.There is a screw at the end of the tool which makes use of the incline plane to move up or down.
The problem situation is when the screen of your MacBook suddenly slams shut for whatever reason,possibly causing damage to your computer and possibly any part of your body.
6th and 7th Photo:
Linkages can be used to improve the situation.When the screen is fully opened,the angle between the linkages is less than 180 degrees,and a piece prevents it from going any further.When a force is applied to close the screen,the linkages will function as a single piece and prevent the screen from closing.