Definitions (words) - Unit 1

Question	Answer
Power	Rate of doing work
Power	one watt (W) is equal to one joule per second
Hooke's Law	The extension of a material is directly proportional to the force extending it
plastic behaviour	a material which does not return to its original length when an extending force is removed - it is permanently distorted
elastic behaviour	material which returns to its original length when an extending force is removed
Global Positioning System	using trilateration between three salellites to position the car on the fourth surface (fourth plane). Using a microwave signal sent from the satellite, the in-car GPS is able to work out the distance between itself and the satellite (using distance = speed of light * time). This is repeated for the other salellites and the point the three spheres intercept, along with the surface of the earth, is the location of the car.
Tensile forces	forces stretching an object - causing tension
compressive forces	forces compressing the object
work done	1J is the work done when an object is moved 1m in the direction of a 1N force
ductile	material with a large plastic region in its behaviour
brittle	material which shows not elastic behaviour - breaks before it reaches its elastic limit
polymeric	degree of strain can reach up to 300% (unlike ductile ~~50%)
stress	the force per unit ctoss-sectional area
strain	the extension pre unit legnth

Resource summary

	Created by Tech Wilkinson over 10 years ago