The physics around us Εισαγωγή Καθοδήγηση για προετοιμασία A machine is a tool used to make work easier. Simple machines are simple tools used to make work easier. Compound machines have two or more simple machines working together to make work easier. In science, work is defined as a force acting on an object to move it across a distance. Pushing, pulling, and lifting are common forms of work. Furniture movers do work when they move boxes. Gardeners do work when they pull weeds. Children do work when they go up and down on a see-saw. Machines make their work easier. The furniture movers use a ramp to slide boxes into a truck. The gardeners use a hand shovel to help break through the weeds. The children use a see-saw to go up and down. The ramp, the shovel, and the see-saw are simple machines. This pathway will help students both to understand and discover the world around them simple mechanisms. Levers, pulleys, screws are used daily. The teacher should prepare a small presentation with the proposed pictures, videos and relative material. The students worksheets should be printed and handed to the students prior to the visit. Short Description: Students will observe importance of simple mechanisms for our live Keywords: Simple mechanisms, lever, reel, equilibrium, pulley Target audience: Teacher Age range: 14 15 years old Context: School, museum Time required: Pre Visit 40 minutes Visit 60 minutes Post Visit 20 minutes
Technical Requirements: computer with internet connection, projector Author s background: school physics teacher Connection with the curriculum: Golden rule of mechanics Learning Objectives: Students learn to know different simple mechanisms Σύνδεση με τη διδακτέα ύλη physics, Golden rule of mechanics, The students learn different simple mechanisms and students will observe the importance of simple mechanisms for our life. Φάση προ-επίσκεψης Πρόκληση της περιέργειας Fisherman caught a big fish and decided to see how much it weigh. How can he measure the weight if he has a bread with a mass of 1 kg and a fishing rod? Προσδιορισμός ερωτήσεων με βάση την υφιστάμενη γνώση How we use the lever and pulley every day?
Πρόταση προκαταρκτικών εξηγήσεων ή υπόθεσης Lever - rigid rod that rotates around a stationary bearing axis. http://www.youtube.com/watch?v=us2kfo_yrpa Σχεδιασμός και υλοποίηση απλής διερεύνησης
What is a lever? Elements of the lever Types of levers Condition for equilibrium What is a reel? Types of reels What is a pulley? Golden rule of mechanics Φάση επίσκεψης Συλλογή αποδεικτικών στοιχείων μέσω παρατήρησης The major principles "see, touch, understand" inspire a huge interest. The success of this non-standard approach is the reason to be applied the same principles in the demo office of physics at the permanent exhibition of the museum. They are priorities also in the training programs "The colour", "Radio-activity without secrets", "The simple machines", "The ozone the shield of the planet", as well as the permanent exhibition in the Palace of physics Εξήγηση βασισμένη στα αποδεικτικά στοιχεία Put text here
Θεώρηση άλλων εξηγήσεων http://www.polytechnicmuseum.org/index.php?lang=en Φάση μετά την επίσκεψη Έκφραση εξηγήσεων Levers are used to lift heavy weights with the least amount of effort. In the example opposite, the heavy weight on the left hand side is been lifted by the person because of the lever. The longer the 'rod' the easier it is to lift the weight. Under normal circumstances the person would not be able to lift the weight at all. The fulcrum is the place where the rod pivots (or rotates). The load is the scientific name for the weight. The effort is quite simply the amount of effort used to push down on the rod in order to move the weight We use levers in every day life. Bicycle brakes work due to the fact that they are based on a lever. The diagram opposite shows the fulcrum and the effort. Another good example of a lever is a simple door handle or a wheel barrow. Draw three examples of levers that are used in everyday life.there are three classes of lever and each class has fulcrum, load and effort which together can move a heavy weight. The fisherman catches the fish which becoms load at the end of the lever. The gardaner uses a wheel baroow to lift tools and garden waste. The load is in the centre of the barrow. The workman uses the trolley to move the large packing case. The fulcrum is the wheel.
http://www.youtube.com/watch?v=9t7tgosxm58&feature=related Δραστηριότητες και υλικά μεταπαρακολούθησης Put text here Στοιχεία επαφής Gosheva Milena physics teacher at a vocational school of electronics "John Atanasov", Sofia, Bulgaria milena_mig@abv.bg