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Mats & performance
21st Century additional applied Science Materials and Performance
Question | Answer |
---|---|
Definition: A material through which electricity can pass easily | Electrical conductor |
What do you call a strip of two metals joined together which have different thermal expansivities? | Bimetal strip |
Which type of lens is a camera lens? | Convex or converging lens |
What is special about elastic materials? | They spring back to their original shape after the force deforming them is removed |
What symbol do the British Standards Institution (BSI) use to show that products match their standards? | Kitemark |
What does compressive strength mean? | The maximum load that a material of standard shape and size can withstand before crumbling |
What is a composite? | A material made up of 2 or more materials combined, which combines the properties of the constituent materials |
What do acoustically hard materials do to sound? | Reflect it |
What do acoustically soft materials do to sound? | Absorb it |
What group of materials do brick, tiles and crockery all belong to? | Ceramics |
Which property defines materials that will snap cleanly and sharply in an impact? | Brittle |
Which formula can be used to predict the extension of an elastic material? | force constant k = force / extension |
What does the area under a force-extension graph tell you? | How much energy is stored in the stretched material |
Definition: A metallic material which is a solid solution of one metal in another, or of a non-metal in a metal | Alloy |
What is the corrosion resistance of a material? | The ability of a material not to take part in corrosion reactions |
Which formula can be used to calculate momentum? | Mass x Velocity |
Which formula can be used to calculate change in momentum? | Force x Collision time |
Which piece of equipment in the car is designed to slow down the forward motion of the driver's head in a crash? | Airbag |
How does a cycle helmet reduce forces acting on the head? | By spreading the impact over a larger area |
What happens to the glass and aluminium of a greenhouse in winter? | They shrink |
Which piece of equipment is used to measure the current in a circuit? | Ammeter |
Which piece of equipment is used to measure the potential difference in a circuit? | Voltmeter |
Which type of circuit has the components following one after each other, with just one path for the current to follow? | Series |
Which type of circuit has more than one path for the current to travel down? | Parallel |
Which formula can be used to calculate electrical conductance? | Current / potential difference |
What is the unit for electrical conductance? | Siemens |
What are most metal fillings made out of? | Amalgam |
Which type of material scatters light as it passes through, meaning that clear images cannot be seen? | Translucent |
What is the name of the point to which parallel rays of light converge having passed through a lens? | Focus |
Which formula can be used to calculate the power of a lens? | 1 / focal length |
Definition: A measure of how much a material changes the direction of light rays at its surface. | Refractive index |
What is the name of the long and very thin fibres made of pure glass and used to transmit pulses of laser light over many kilometres? | Optical fibres |
Definition: A specification standard beyond the minimum necessary to prevent an accident. | Safety margin |
What type of lens do luminaires (stage lights) use? | Fresnel lens |
How is sound caused? | Vibrations |
What is the intensity of sound measured in? | Decibels |
What happens to the loudness of a sound as its intensity increases by 10dB? | It doubles |
What is frequency measured in? | Hertz |
What is the name of the condition where ringing in the ear doesn't go away? | Tinnitus |
What are the structures used on bridges and buildings to absorb vibrations? | Fluid-filled dampers |
What property is described by the stretching force needed to break a material? | Tensile strength |
Which formula can be used to calculate density? | mass / volume |
Definition: The distance between the lens and its focal point. | Focal length |
What is the name of the opening that lets light into a camera when the shutter is open? | Aperture |
What unit is used to measure the power of a lens? | Dioptre |
What is the name of an image that cannot be formed on a screen? | Virtual image |