GCSE AQA Physics

• A scalar quantity is a number.
• A vector quantity is a number and a direction, for example, distance is scalar, but displacement is vector, because it's distance in a direction.
• Mass is scalar, but weight, which is your mass upon the Earth, is vector.
• Speed is scalar, but velocity, which is speed in a certain direction, is vector.
• Acceleration and force are both vector.
• Momentum is also vector.
• If we're looking for the resultant force, we need to find the difference between them, for example, here we have 10 plus 10 newtons minus five newtons is going to give us plus five newtons, which is going to be five newtons in that direction.
• Your weight is not the same as your mass, because your weight is equal to your mass times gravity.
• Work equals force times distance, work is measured in joules, force is measured in newtons, and distance is measured in meters.
• When you exert a force on an object, it is going to be squashed or stretched or deformed in some way, this is commonly known as Hooke's Law.
• Kinetic energy is equal to 1/2 times mass times velocity-squared, kinetic energy is measured in joules, mass is measured in kilograms, and velocity is measured in meters per second.
• Mass is measured in kilograms.
• Stopping distance for a car is made up of thinking distance and braking distance.
• A transverse wave goes up and down from one point to another point, with the wavelength measured from one point to another point, the amplitude measured from the middle to the top or from the middle to the bottom, the direction of movement is up and down, the direction of oscillation is sideways, and the direction of energy transfer is sideways.
• The momentum is measured in kilograms, with a space, meters per second.
• For every action, there is an equal and opposite reaction.
• Force is measured in newtons.
• Force equals mass times acceleration.
• Thinking distance is the distance your brain needs to process the image before sending a signal to your foot.
• Braking distance is the distance a car takes to stop, which is affected by the conditions of the tires and the weight of the car.
• Seat belts, baby seats, crumple zones, air bags, and other safety features are designed to make a car safer.
• The speed of a wave can be measured using a ripple tank, with the equation V equals f times lambda.
• Momentum is mass times velocity.
• Acceleration is measured in meters per second-squared.
• Velocity is measured in meters per second.
• The law of conservation of momentum states that momentum is always conserved, meaning your momentum before is equal to your momentum afterwards.
• A longitudinal wave has areas of compression and areas of refraction, with the wavelength measured from one point to another point, the direction of movement is side-to-side, the direction of energy is side-to-side, and the direction of energy transfer is side-to-side.
• Things that affect thinking distance are drinking alcohol, taking illegal drugs, and being tired.
• Frequency is the number of waves per second, measured in hertz.
• A fluid can either be a liquid or a gas, liquids are incompressible, and the exam boards like that word, whereas gases are compressible.
• Pressure equals force over area, the units of pressure are pascals, for force it is newtons, and for area it is meters-squared.
• Pressure, with a P, equals height times density, which is a lowercase rho, times gravitational field strength, pressure is measured in pascals, height is measured in meters, and density is measured in kilograms per meters-cubed.
• When a wave is reflected, it is going to come in, meet the boundary and then be reflected off, with our angle of incidence always equal to our angle of reflection, i equals r.
• The range of human hearing is 20 hertz to 20 kilohertz.
• A sound wave is a longitudinal wave that vibrates the air particles, which the ear drum picks up and turns into sound.
• The greatest force in a simple electric motor is when the wire is perpendicular with magnetic field lines, and the force is zero if the wire and the field lines are parallel.
• A moving coil microphone works with the same principle but in the opposite direction, with sound causing the diaphragm to vibrate, moving the coil backwards and forwards past the magnet.
• Force is equal to mass times the change in velocity over the change in time.
• A vessel exploring the sea can send down an ultrasound and measure the time it takes to come back, with the time taken being shorter or longer depending on the distance.
• Magnetic flux density is the amount of magnetic flux in a certain area, and the equation for this is force equals magnetic flux density times current times length.