OCR A LEVEL PHYSICS MODULE 3 Summary and Study Guide for Rapid Revision

▪ The gradient of a distance-time graph - Ansspeed ▪ average speed - Ansdistance travelled / time taken ▪ velocity - Ansrate of change of displacement ▪ acceleration - Ans rate of change of velocity ▪ area under a velocity-time graph - Ans displacement ▪ gradient of a velocity-time graph - Ans acceleration ▪ stopping distance - Ans thinking distance + breaking distance ▪ thinking distance - Ans the distance travelled between the moment a hazard is spotted to the moment the breaks are applied ▪ breaking distance - Ans the distance travelled from the time the brake is applied until the vehicle stops ▪ reaction time - Ans thinking distance / speed ▪ acceleration of free fall - Ans9.8ms^-2 ▪ 1 newton - Ans force required to give a mass of 1kg an acceleration of 1ms^-2 ▪ Weight - Ans mass x gravitational field strength ▪ centre of gravity - Ans point at which the entire weight appears to act through ▪ condition for terminal velocity - Answeight = drag ▪ moment - Ansforce x perpendicular distance to the line of action of force from axis or point of rotation ▪ principle of moments - Ans for a body in rotational equilibrium, the sum of the anticlockwise moments about any point is equal to the sum of the clockwise moments about the same point ▪ torque of a couple - Ans one of the forces x perpendicular separations between the forces ▪ density - Ans mass per unit volume ▪ pressure - Ans force per unit cross-sectional area ▪ Archimedes' principle - Ans the upthrust exerted on a body immersed in a fluid is equal to the weight of the fluid the body displaces ▪ work done - Ans force x distance moved in the direction of the force ▪ principle of conservation of energy - Ans the total energy of a closed system remains constant: energy can never be created or destroyed, only transferred from one form to another ▪ equation for kinetic energy - Ans 1/2mv^2