P2 physics exam 2 3.0 / 5 based on 1 rating ? PhysicsForces and MotionGCSE Created by: grace bryantCreated on: 23-05-11 08:49 velocity and acceleration Speed and Velocity both how fast you are going distance = speed x time Acceleration is how quick you speed up change in velocity = acceleration x time taken 1 of 9 d-t and v-t DT VT gradient = speed gradient = acceleration flat = stopped flat = steady speed downhill = going back uphill = acceleration curves = acceleration downhill = deceleration area under = distance travelled curve = change in acceleration 2 of 9 mass and weight and gravity Gravity is the force of attraction between all masses on earth's surface makes things accelerate (10m/s2) gives everything a weight makes things orbit Mass = amount of stuff in an object (same anywhere) kg Weight = force of gravity (changes) N W = m x g 3 of 9 the laws of motion First Law. balanced forces mean no change in velocity Second Law. a resultant force means acceleration f = ma Third Law. if object A exerts a horce on object B then object B exerts the exact opposite force on object A 4 of 9 drag and terminal velocity Steady Speed - Driving Force = Frictional Force drag increases as speed increases resistance is reduced when more stream lined Falling Objects Accelerate until resistant force = Accelerating force Terminal Velocity depends on shape and area 5 of 9 stopping distances Stopping Distance = Thinking Distance + Braking Distance Thinking - tiredness, drugs, alcohol, age, surrondings Braking - the load, brakes, road, weather, tyres 6 of 9 work done Means energy transferred (J) When work is done energy is used this energy is the work done Work Done is the wasted and useful energy work done = force x distance 7 of 9 kinetic and potential energy Kinetic Energy is Movement Energy kinetic energy = 1/2 x mass x velocity2 Stopping distance increases alarmingly with extra speed because the velocity is squared Potential energy is stored energy Springs have it, it is releases as KE Higher an object more gravitational potential energy 8 of 9 momentum and collisions momentum = mass x velocity momentum has size and direction momentum before = momentum after change in mo = force acting x time taken crumple zones increase time taken seat belts increase time taken air bags increase time taken 9 of 9
Comments
No comments have yet been made