PHYSICS DEFINITIONS ⚠️ A Level, Edexcel Exam Questions And Answers 2024

Speed - correct answer-The rate of change of distance Velocity - correct answer-The rate of change of displacement Displacement (mechanics) - correct answer-The vector measurement of distance in a certain direction Vector Quantity - correct answer-Has both magnitude and direction Scalar Quantity - correct answer-Has only magnitude Average speed - correct answer-Calculated by dividing the total distance for a journey by the total time for the journey Instantaneous speed - correct answer-The speed at any particular instant in time on a journey, which can be found from the gradient of the tangent to a distance-time graph Acceleration - correct answer-The vector defined as the rate of change of velocity Displacement-time graph - correct answer-A graph showing the positions visited on a journey, with displacement on the y-axis and time on the x-axis Velocity-time graph - correct answer-A graph showing the velocities on a journey, with velocity on the y-axis and time on the x-axis Resultant force - correct answer-The total force (vector sum) acting on a body when all the forces acting are added together accounting for their directions Free-body force diagram - correct answer-Has the object isolated, and all the forces that act on it are drawn in at the points where they act, using arrows to represent the forces Equilibrium - correct answer-When there is zero resultant force and zero resultant moment; zero acceleration Principle of moments - correct answer-A body will be in equilibrium if the sum of clockwise moments acting on it is equal to the sum of anti-clockwise moments Centre of gravity - correct answer-The point through which the weight of an object appears to act Newton's first law of moments - correct answer-An object will remain at rest, or in a state of uniform motion, until acted upon by a resultant force Newton's second law of moments - correct answer-If an object's mass is constant, the resultant force needed to cause an acceleration is given by the equation F = ma Newton's third law of motion - correct answer-For every action, there is an equal and opposite reaction Kinematics - correct answer-The study of the description of the motion of objects Uniform motion - correct answer-Motion when there is no acceleration Resolution / resolving vectors - correct answer-The determination of a pair of vectors, at right angles to each other, that sums to give the single vector they were resolved from Projectile - correct answer-A moving object on which the only force of significance acting is gravity. The trajectory is thus pre-determined by its initial velocity Gravitational potential energy - correct answer-The energy an object has by virtue of its position in a gravitational field Kinetic energy - correct answer-The energy an object has by virtue of its movement Conservation of energy - correct answer-The rule that states that energy can never be created or destroyed Work done - correct answer-The product of a force and the distance moved in the direction of the force Energy - correct answer-The property of an object that gives it the capacity to do work. A change in the amount of energy of an object could be equated to work being done Power - correct answer-The rate of energy transfer Efficiency - correct answer-The ability of a machine to convert energy usefully Momentum - correct answer-Mass x velocity Conservation of linear momentum - correct answer-The vector sum of the momenta of all objects in a system is the same before and after any interaction between the objects Explosion - correct answer-A situation in which a stationary object separates into component parts, which move off at different velocities. Momentum must be conserved in explosions