5. Displacement, distance and speed

Available for over a year

In this episode, James Stewart and Ellie Hurer explore distance, displacement and speed. The difference between these terms and how to calculate them. Suitable for: AQA, Edexcel, OCR. For more information on displacement, distance and speed, check out the BBC Bitesize website: https://www.bbc.co.uk/bitesize/guides/zwc7pbk/revision/1 Key learning objectives discussed in this episode: - Distance is how far an object moves. Distance does not involve direction. - Distance is a scalar quantity.Displacement includes both the distance an object moves, measured in a straight line from the start point to the finish point and the direction of that straight line. Displacement is a vector quantity. - Students should be able to express a displacement in terms of both the magnitude and direction. - Speed does not involve direction. Speed is a scalar quantity. - Students should be able to make measurements of distance and time and then calculate speeds of objects. - For an object moving at constant speed the distance travelled in a specific time can be calculated using the equation: - Distance travelled = Speed × Time - Students should be able to calculate the average speed for non-uniform motion. - The velocity of an object is its speed in a given direction. Velocity is a vector quantity - The average acceleration of an object can be calculated using the equation: acceleration = change in velocity - time taken - The following equation applies to uniform acceleration: - Final Velocity 2 − Initial Velocity 2 = 2 × Acceleration × Distance - Near the Earth’s surface any object falling freely under gravity has an acceleration of about 9.8 m/s2. - An object falling through a fluid initially accelerates due to the force of gravity. Eventually, the resultant force will be zero and the object will move at its terminal velocity.