© John Parkinson 1

© John Parkinson 2 Distance travelled - s Time taken - t Velocity - v v= s t v s / t Velocity = Speed in a Specified Direction Constant Velocity

© John Parkinson 3 N 100 m in 4 seconds Distance travelled = ?100 m Displacement = ? 100 m to the East Speed = ?Speed = 100/4 = 25 m s -1 Velocity = ? Velocity = 25 m s -1 to the East

© John Parkinson 4 DISPLACEMENT – TIME GRAPHS Constant velocity Displacement - s Time - t What will the graph look like? GRADIENT = ? Δt Δs VELOCITY

© John Parkinson 5 Displacement - s Time - t What about this graph? A body at rest Displacement - s Time - t And this graph? The gradient is …….? increasing Δs Δt The body must be ……..? accelerating

© John Parkinson AVELOCITY – TIME GRAPHS Velocity - v Time - t Velocity - v Time - t This body has a constant or uniform ………? acceleration Δv Δt The gradient = ? the acceleration 1 = …… ? Uniform acceleration 2 = …… ? Constant velocity 3 = …… ? Uniform retardation [deceleration] Area under the graph = A = …….. ? DISTANCE TRAVELLED

© John Parkinson 7 Velocity – v/ms -1 Time – t/s QUESTION The graph represents the motion of a tube train between two stations Find 1.The acceleration 2.The maximum velocity 3.The retardation 4.The distance travelled 1. The acceleration = the initial gradient = 30÷20 = 1.5 m s The maximum velocity is read from the graph = 30 m s The retardation = the final gradient = -30 ÷ [80-50] = m s -2 4.The distance travelled = the area under the graph =½ x 20 x 30 + x + ½ x x = 1650 m

© John Parkinson 8 What will the distance – time, velocity - time and acceleration time graphs look like for this bouncing ball? s1s1 s2s2 Displacement - s Time - t Velocity - v Time - t s1s1 s2s2

© John Parkinson 9 Acceleration - a Time - t Velocity - v Time - t 9.81ms -2