y11 phy

• Speed is a measure of the distance travelled over the time taken, measured in m/s, symbol v
• Acceleration is a change of speed over time, due to unbalanced forces acting on the object, measured in ms^-2, symbol a
• A force is a push or a pull that acts on an object, measured in Newtons, symbol F
• 4 common forces: Support, Friction, Weight, Thrust
• Mass is the amount of matter that something is made of (kg/g). This does not change
• Weight is the downward force due to gravity that an object experiences due to its mass, measured in Newtons (N)
• Gravity is a force of attraction between two objects. Gravity has a greater force on the larger object
• Friction is a force opposite to motion which is created as soon as something starts to slide past something else, measured in Newtons (N)
• Pressure is a measure of force applied to a particular area, measured in Newtons per square metre (Nm^-2) or using the units of Pascals (Pa)
• Pressure is increased by increasing the force in the same area or reducing the area the force is applied to
• Gravitational potential energy is the energy stored in an object due to its height above Earth, measured in Joules (J)
• Energy cannot be created or destroyed, only transferred or transformed
• An object has kinetic energy when it is moving. Kinetic energy is the energy of motion, measured in Joules (J)
• Work is the transformation of energy
• Work done is the amount of energy transformed which is the change in energy gain or loss of energy
• Work is done when a force causes an object to move a distance in the direction of the force
• When a force is applied to an object of mass and moves it over a distance then work has been done. To do 1 Joule of work you need 1 Joule of energy
• Power is a measure of work done over time, measured in watts (W). A watt is one joule per second
• Power is also the rate at which energy is transformed, measured in watts (W)
• Current in series: I(total) = I(1) = I(2) = I(3)
• Voltage in series: V(total) = V(1) + V(2) + V(3)
• Resistance in series: R(total) = R(1) + R(2) + R(3)
• Current in Parallel = I(total) = I(1) + I(2) + I(3)
• Voltage in parallel: V(total) = V(1) = V(2) = V(3)
• Resistance in parallel: 1/R(total) = 1/R(1) + 1/R(2) + 1/R(3)
• In series as total RT ↑ overall power decreases. Because as RT increases IT decreases so Power will decrease in a squared amount against I
• In parallel as total RT ↓ overall power increases. Because as RT decreases IT increases so Power will increase in a squared amount against IT
• Conductors are substances that allow electrons to flow freely through them.
• Insulators are substances that do not allow electrons to flow freely through them.