Created by sophiewalkerrock
over 7 years ago


Question  Answer 
Acceleration  The rate of change of an objects velocity. a=v/t Unit: ms2 
Average Speed  Total distance travelled by an object divided by the total time taken. 
Braking distance  The distance travelled by a vehicle from the moment when the brakes are applied until the vehicle comes to a stop. 
Brittle  Describes a material that shows no plastic deformation and breaks just beyond its elastic limit. 
Centre of Gravity  The point where the entire weight of an object appears to act. 
Components (of a vector)  The magnitudes of a vector quantity in two perpendicular directions. 
Compressive  A force that squeezes an object 
Density  The mass per unit volume of a material. p=m/V Unit: kgm3 
Displacement  The distance moved by an object in a particular direction(measured from a fixed starting point) 
Ductile  Describes a material that can easily be drawn into wires (e.g. copper) 
Dynamics  A study of motion involving force and mass. 
Efficiency  The ratio of useful output energy to the total input energy for a device, expressed as a percentage. Efficiency= Useful output energy x100 Total input energy 
Elastic  Describes a material which will return to its original shape once the forces are removed. 
Elastic Limit  The value of stress beyond which an object will not return to its original dimensions. 
Elastic Potential Energy  Energy stored in an extended or compressed material. 
Equations of motion 
Image:
linearformula (image/png)

Equilibrium  An object in equilibrium is either at rest or travelling with a constant velocity because the net force on it is zero. 
Extension  The change in the length of a material from its original length. 
Force Constant  The ratio of force to extension for a spring or a wire. Unit: Nm1 
Gravitational Potential Energy  Energy stored by an object by vitue of its position in the Earths gravitational field. 
Hooke's Law  The extension produced in an object is proportional to the force producing it, provided the elastic limit is not exceeded. 
Inertia  A measure of the mass of an object. A massive object has a large inertia. 
Instantaneous speed  The speed of an object measured over a very short period of time. 
Kilowatt hour  The energy transferred by a 1kW device in a time of 1 hour. 1kWh= 3.6 kJ 
Kinematics  A study of motion using quantities such as time, distance, displacement, speed, velocity and acceleration. 
Kinetic Energy  Energy of an object due to its motion 
Mass  A measure of the amount of matter within an object. Unit: Kilograms 
Moment  The moment of a force about a point is the magnitude of the force, multiplied by the perpendicular distance of the point from the line of the force. Unit: Nm 
Newton  The force that will give a 1kg mass an acceleration of 1ms2 in the direction of the force. 1N = 1kgms2 
Plastic Deformation  The deformation of a material past its elastic limit. 
Power  The rate at which energy is transferred or the rate at which work is done. Unit: watt (W) 
Pressure  The force acting normally per unit area of a surface. p=F/A Unit: Nm2 or Pa 
Principal of Moments  The sum of clockwise moments about a point is equal to the sum of anticlockwise moments about the same point. 
Projectile  Any object thrown in the Earths gravitational field. 
Range  The horizontal distance covered by an object. 
Resultant Force  The net force acting on an object. 
Scalar Quantity  A scalar quantity has magnitude but no direction. 
Speed  The rate of change of the distance moved by an object. Speed = Distance/time Unit: ms1 
Stopping Distance  The sum of the thinking distance and the braking distance 
Strain  The extension per unit length produced by tensile or compressive forces. Strain= extension original length 
Stress  The force acting per unit crosssectional area. Stress= Force Crosssectional area Unit: Nm2 
Tensile  A term used to denote tension or pull 
Terminal velocity  The constant velocity of an object travelling through a fluid. The net force of an object is zero. 
Thinking distance  The distance travelled by a vehicle in a time equal to the reaction time of the driver. 
Torque  The product of one of the forces of a couple and the perpendicular distance between them. Unit: Nm 
Ultimate Tensile Strength (UTS)  The breaking stress of a material. UTS = Breaking force Crosssectional area 
Uniform Acceleration Uniform Motion  Acceleration that remains constant. Motion of an object travelling with a constant acceleration. 
Vector Addition Vector Triangle  Using a drawing, often to scale, to find the resultant vector. A triangle drawn to determine the resultant of two vectors. 
Vector Quantity  A vector quantity has both magnitude and direction. 
Velocity  The rate of change of the displacement of an object. Velocity = Change in displacement time Unit: ms1 
Weight  The force of an object caused by a gravitational field acting on its mass. Weight = mass x acceleration of free fall Unit: newtons (N) 
Work Done  The product of the force and the distance moved by the force in the direction of travel. 
Young Modulus  The ratio of stress to strain for a given material, resulting from tensile forces, provided Hooke's law is obeyed. Young modulus=Stress/strain Unit: Pa 