physics impt

• in displacement-time graph, line represents displacement.
• in displacement-time graph, gradient represents velocity
• in velocity-time graph, area under graph represents displacement
• in velocity-time graph, line represents velocity
• in velocity-time graph, gradient represents acceleration
• in acceleration-time graph, line represents acceleration
• in acceleration-time graph, area under graph represents velocity
• Pressure is defined as the force acting normally per unit area.
• Hydraulic systems work because liquids are almost incompressible and they transmit pressure equally in all directions
• Temperature measures the degree of 'hotness' or 'coldness' of a body.
• Brownian motion provides evidence for the theory that matter is made up of particles in continuous random motion.
• Conduction is the transfer of thermal energy through a medium without any flow of the medium.
• Convection is the transfer of thermal energy by means of convection currents in a fluid (liquid or gas) due to a difference in density.
• Radiation is the transfer of thermal energy in the form of electromagnetic waves (e.g. infrared radiation) without the aid of a medium.
• Heat capacity is the amount of thermal energy required to raise the temperature of the body by 1 °C (or 1 K), without any change of state.
• Specific heat capacity is the amount of thermal energy required to raise the temperature of unit mass of the substance by 1 °C (or 1 K), without any change of state.
• Latent Heat is the amount of thermal energy needed to change a substance from solid state to liquid state or from liquid state to a gaseous state, without any change in temperature.
• Specific Latent Heat of fusion is the amount of thermal energy needed to change unit mass of a substance from solid state to liquid state, without any change in temperature.
• Specific Latent Heat of vaporisation is the amount of thermal energy needed to change unit mass of a substance from liquid state to gaseous state, without any change in temperature.
• A wave is a disturbance that propagates through space, transferring

  energy with it but not matter.
• Wavelength (λ) is the distance between two successive crests or two

  successive troughs in a wave.
• Period (T) is the time taken to generate one complete wave.
• Amplitude (A) is the magnitude of the maximum displacement from the rest position.
• Speed (v) is the .distance moved by a wave per unit time
• Frequency (f) is the number of crests (peaks) or troughs that pass a point per second
• Wavefront is the line joining all the points which are in phase
• Longitudinal waves are waves which travel in a direction parallel to the direction of vibrations.
• Transverse waves are waves which travel in a direction perpendicular to the direction of vibrations.