Available online
Description
The programme defines energy transfers to a control mass by working and heating. It goes on to show that internal energy is a new thermodynamic property.
The programme defines energy transfers to a control mass by working and heating. It goes on to show that internal energy is a new thermodynamic property.
| Module code and title: | T231, Introduction to engineering mechanics |
|---|---|
| Item code: | T231; 10 |
| First transmission date: | 15-06-1975 |
| Published: | 1975 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:23:53 |
| + Show more... | |
| Producer: | Andrew Crilly |
| Contributors: | John Cannell; Richard Pefley |
| Publisher: | BBC Open University |
| Keyword(s): | Conservation of energy; Efficiency; Electrical generating plant; Energy storage; Perpetual motion |
| Footage description: | John Cannell introduces the programme. He has with him what appears to be a perpetual motion machine. Dick Pefley explains the form which this programme and the next will take. John Cannell discusses man's historical need for energy. Still shots of primitive men with bows and arrows, ploughing, etc. Cannell explains the concept of work and then defines 'systems' in a thermodynamic context. He draws a simple, schematic thermodynamic system on a board which shows work and heat as energy transfer processes. Cannell next looks at a diagram of a simple system which has both work and heat inputs. This system illustrates the points he has made above. Cannell explains that these energy inputs result in stored, internal energy for the system. Shots of pendulum, pyramids, dams and bottles of chemicals are shown as examples of systems with stored, internal energy. Cannell states the first law of thermodynamics and writes it on a board in the form of an equation. Cannell examines the relationship between pressure, temperature and volume in the first law. He draws a simple system (a cylinder sealed by a piston) to illustrate his points. Cannell describes, graphically, a change of state within a system. He goes on to show that internal energy is another property of state. From this he demonstrates that perpetual motion machines are impossible. Dick Pefley applies the first law to a practical example. He uses a model of a steam power station and a schematic diagram of this system to calculate energy inputs and outputs. A brief question and answer session with students in the studio completes the programme. |
| Master spool number: | 6HT/71803 |
| Production number: | 00525_5110 |
| Videofinder number: | 2226 |
| Available to public: | no |
