Physics

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• Created by: eimeart
• Created on: 29-03-15 19:36
What is energy?
Energy is the ability to do work. Energy is measured in Joules(J).
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What are types of energy?
Forms of energy include kinetic, sound, light heat, potential, chemical, nuclear and electrical.
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What is the law of conservation of energy?
Energy cannot be created or destroyed, it can only be changed from one form to another. A toaster converts electrical energy to heat energy. A torch converts electrical energy to light energy.
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What is mass?
Mass is the amount of matter in an object. Mass is measured in kilograms(kg) or grams(g).
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What is density?
Density is the mass in 1cm3 or 1m3 of a substance. An object is dense if the matter in it is packed very tightly. Density is measured in g/cm3 or kg/m3. Density is determined by measuring the mass, then the volume, and dividing the mass by the volume
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What is Floatation?
An object floats in a liquid if its density is less than the density of the liquidThe density of water is 1g/cm3. Substances with a density less than this will float in water, those with a density greater than this will sink..
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What is Force?
A force is anything which can change the velocity of an object or make it move. Force is measured in Newtons(N).
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What is Friction?
Friction is a force which prevents the easy movement between two objects in contact.
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What is Hookes law?
Hooke's Law states that the extension of a spring depends on the force pulling on it (e.g. the weight of a mass attached to the spring).
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What is work?
Work is done when a force moves an object. Work is measured in Joules. Work(J) = Force(N) X Distance(M).
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What is Power?
Power is the rate at which work is done. Power is measured in watts. 1 Watt = 1 Joule per second. The average power(watts) is the work done(joules) divided by the time taken(seconds).
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What is speed?
Speed is the distance travelled per unit time. Speed in measured in m/s or ms-1 Speed = distance divided by time.
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what is velocity?
Velocity is speed in a given direction. Velocity is measured in m/s or ms-1
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What is acceleration?
Acceleration is the change in velocity per second. Acceleration is measured in m/s/s or m/s2 or ms-2 Acceleration = change in velocity divided by time.
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What is a moment?
A moment is the turning effect of a force. It is equal to the force multiplied by the distance.
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What is a lever?
A lever is a rigid body that can rotate around a fixed point. The fixed point is known as the fulcrum.
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What is the law of the lever?
The law of the lever states that when a lever is balanced the clockwise moment is equal to the anticlockwise moment.
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What is the centre of gravity?
The centre of gravity is the point in a structure where all of the weight can be thought to act.
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What are the different forms of equilibrium?
An object is in stable equilibrium if it has a wide base and a low centre of gravity. An object is in unstable equilibrium if a vertical line going through its centre of gravity would fall outside its base. An object is in neutral equilibrium
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What is light?
Light is a form of energy.
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What is reflection?
Reflection is when light bounces off a surface. When light hits a reflective surface (e.g. a mirror) at an angle, it is reflected at the same angle.
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What is refraction?
Refraction is the bending of light as it passes from one medium to another. The ray of light is refracted towards the denser medium.
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What is dispersion of light?
White light is made up of seven different colours - red orange, yellow, green, blue, indigo and violet. These are called the spectrum of white light. Dispersion is the breaking up of white light into its seven different colours.
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What is a lens?
A lens is a piece of glass with a curved surface. Convex lenses bends light rays together. A concave lens spreads out the rays of light.
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What is heat?
Heat is a form of energy. It is measured in Joules (J).
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How does heat travel?
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What is sound?
Sound is a form of energy. Sound is measured in decibels(dB). Sound needs a medium to pass through - it cannot travel through a vacuum. Sound travels at 340m/s.
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What is electric current?
Electric current is the flow of electric charge. Current is measured in amps(A) by using an ammeter.
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What is resistance?
Resistance is the ability of a substance to resist the flow of electricity. It is measured in ohms.
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What is ohm's law?
Ohm's law states that at constant temperature the voltage (V) is directly proportional to the current in a circuit (I). Voltage (V) = Current (I) X Resistance (R).
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What is a fuse?
A fuse is a device which cuts off the current in a circuit if it goes above a particular level. The wire in the fuse overheats and melts, breaking the circuit. Circuit breakers are now used instead of fuses.
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What are the wires in a plug?
The live wire is brown and is located on the right. The neutral wire is blue and is located on the left. The earth wire is yellow/green and is located in the middle
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What is a diode?
A diode is a component that allows electricity to flow in one direction only.
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What is static electricity?
When two objects are rubbed together, electrons are transferred between them. Certain substances do not allow electricity to flow through them, and as a result they can build up an electric charge. This is known as static electricity.
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Other cards in this set

Card 2

Front

What are types of energy?

Back

Forms of energy include kinetic, sound, light heat, potential, chemical, nuclear and electrical.

Card 3

Front

What is the law of conservation of energy?

What is mass?

What is density?