KEY WORDS: Velocity Acceleration Deceleration Speed ASSESSMENT: P2 REVISION – CHAPTER 1 – Motion Distance-time Graphs The gradient of the line on a distance-time graph represents _________. The ______________ the gradient, the greater the speed. If an object is stationary, the line on a distance-time graph is ______________. If an object is moving at a constant speed, the line on a distance-time graph is a straight line that slopes _____________. Velocity & Acceleration If the value calculated for acceleration is negative, the body is decelerating – slowing down. A deceleration is the same as a negative acceleration. Velocity-time graphs The gradient of the line on a velocity-time graph represents ______________. The steeper the ____________, the greater the acceleration. What does a horizontal line show on a velocity-time graph? What area on a velocity-time graph shows the distance? Using Graphs Calculate the gradient of the line on a distance-time graph to give you the speed of an object. Calculate the gradient of the line on a velocity-time graph to give you the acceleration of an object.

KEY WORDS: Force Newton Mass ASSESSMENT: Forces between objects. P2 REVISION – CHAPTER 2 – Forces Stopping distance Distance travelled during the thinking distance, plus the distance it travels under the braking distance Thinking distance Is increased if the driver is tired or under the influence of _____________ or __________. Braking distance Can be increased by: Poorly maintained roads Bad weather conditions. Condition of the car: eg: Worn ____________ Forces are measured in newtons, N. What is the rule with regard to forces? Resultant Force The resultant force is a single force that has the same effect as all the forces acting on an object. If an object is accelerating there must be a resultant force acting on it. If an object is accelerating what 3 things can it be doing? Force and Acceleration What always causes an acceleration? The bigger the resultant force on an object, the greater its ___________________. F = m x a F is the resultant force in newtons, N. m is the mass in kilograms, kg a is the acceleration in m/s² Acceleration is a change in velocity. An object can accelerate by changing its ________________ even if it is going at a ______________ ____________. Therefore a ___________________ ______________ is needed to make an object change __________________. On the Road If a vehicle is travelling at a steady speed, the resultant force on it is __________. The driving forces are equal and opposite to the frictional forces. Reaction time depends on the ____________. Braking distance depends on the ___________, ___________ _____________ and the condition of the vehicle.

KEY WORDS: Gravitational Drag force Terminal velocity Weight Elastic Proportionality ASSESSMENT: P2 REVISION – CHAPTER 2 – Forces continued. Falling Objects The force of gravity is called ___________ An object acted on only by gravity will accelerate at about ___________. F = m x a Where: F is the resultant force in newtons, N. m is the mass in kilograms, kg a is the acceleration in m/s² Becomes: W = m x g Where: W is the weight in newtons, N m is the mass in kilograms, kg g is the acceleration due to gravity in m/s² If an object falls through a fluid the fluid exerts a __________ force on the object. Faster the object falls, the bigger the drag force becomes until it becomes equal to the weight of the object. Resultant force will then be ___________. This is called ________________ _______________. DON’T FORGET: Mass is the amount of matter in an object. Weight is the force of gravity acting on it. Stretching & Squashing What does elastic mean? The extension of a spring is DIRECTLY PROPORTIONAL to the force applied to it, provided the limit of proportionality is not exceeded. How do we know that it is directly proportional? Extension is the difference between the length of the spring and its ____________ _________. Hooke’s Law Equation: F = k x e Where F is the force applied in newtons, N k is the spring constant of the spring in newtons per metre, N/m e is the extension in metres, m What is the spring constant of a spring? Force and Speed Issues Reduces the speed of a vehicle reduces the amount of what? What is this called? Reducing air resistance, making a vehicle more _________________ also improves fuel economy. Speed cameras are used to discourage motorists from doing what? In pairs they can be used to calculate __________________ speed. What happens if you are caught speeding? When does skidding happen? What happens when you skid? _________ ___________ surfaces are used to reduce or prevent skidding. How do these surface work? Where are they used?