“What a lovely morning for a boating party,” said Professor Sinker, as the party of 12 made their way down to the mooring, “the light is Caravaggesque.” The light was indeed spectacular, the dark clouds of a gathering storm contrasting splendidly with morning light, and with steep waves on the lake adding a little drama ..
I have always enjoyed playing with mechanical equipment. As a child I was endlessly fascinated by combination locks on safes, pulley systems, epicyclic gearboxes and the like. Even the humble elastic band can provide hours of entertainment in the right pair of hands. I remember spending days making an huge super-ball that was responsible for ..
I’m not sure if children still play Cat’s Cradle---a game which only required a piece of string. Nimble fingerwork allowed one to create some clever patterns of interwoven lines. Structures that could be passed from one pair of hands hands to another as they morphed and inverted to create new shapes. It’s one of those ..
When I was about seventeen, my brother became interested in nutrition. He had a theory that a diet consisting of only brown rice and butter had sufficient nutritional content to keep a person well nourished for months. A devotee of the the scientific method, he stuck to this diet for an entire summer. So far ..
This variation on Qu121 allows an explicit solution to be calculated. Where the previous puzzle might be regarded as slightly tricky, this is straightforward in the sense that there are no unexpected tricks---it is purely a question of carefully applying methods in statics. A pulley arrangement consisting of a fixed pulley A, a fixed double ..
A window cleaner works in a light suspended cradle attached to a roof structure by a rope. Three pulley configurations A, B and C are available. Assuming the man to be strong, determine for each configuration which of the following is true when the man pulls on the free end of the rope as shown: The ..
A pulley arrangement consisting of a fixed pulley A, a fixed double pulley B, and a free pulley C is attached to two equal masses D and E as shown in the diagram. The pulleys are light and frictionless, and the ropes are light and inextensible. The pulleys are very small in comparison to their separation. The system is initially held in a position ..
I really like this question. Many people struggle with even the easy part, despite thinking they are familiar with how pulleys work. You should try the harder variant to get a more complete understanding of how to use control volume analysis. A man has one single pulley, and one double pulley composed of two wheels mounted ..