https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:kinematics/x0e04e0cb682fb793:speed-and-velocity/v/position_velocity_speed 2024-11-07T15:12:48.053941755Z Position, velocity, and speed An object's position specifies how far the object is from a reference point, and in what direction. The rate that an object's position changes is called velocity. Average velocity is calculated as change in position divided by change in time. Position and velocity are vector quantities. Average speed is calculated as distance travelled divided by time. Speed and distance are scalar quantities with no direction. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/b42f4e45-f832-4988-bcea-732d1348b410_1280_720_base.png Position, velocity, and speed An object's position specifies how far the object is from a reference point, and in what direction. The rate that an object's position changes is called velocity. Average velocity is calculated as change in position divided by change in time. Position and velocity are vector quantities. Average speed is calculated as distance travelled divided by time. Speed and distance are scalar quantities with no direction. https://cdn.kastatic.org/ka-youtube-converted/vOipqtdR23s.mp4/vOipqtdR23s.mp4 624 Describing motion https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:kinematics/x0e04e0cb682fb793:acceleration/v/intro_to_acceleration 2024-06-21T18:55:31.273097146Z Acceleration Acceleration is the rate of change of velocity (a = Δv/Δt). The unit for acceleration is m/s/s, or m/s^2. Acceleration is a vector with magnitude and direction. If velocity and acceleration point the same direction, the object is speeding up. If velocity and acceleration point opposite directions, the object is slowing down. Changing direction is also a form of acceleration. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/5bcc5c04-58ec-4ae7-95a9-50abf4cbd4c0_1280_720_base.png Acceleration Acceleration is the rate of change of velocity (a = Δv/Δt). The unit for acceleration is m/s/s, or m/s^2. Acceleration is a vector with magnitude and direction. If velocity and acceleration point the same direction, the object is speeding up. If velocity and acceleration point opposite directions, the object is slowing down. Changing direction is also a form of acceleration. https://cdn.kastatic.org/ka-youtube-converted/JSPwCtIPfQw.mp4/JSPwCtIPfQw.mp4 620 Describing motion https://www.khanacademy.org/science/highschool-physics/x6679aa2c65c01e53:motion-and-forces/x6679aa2c65c01e53:describing-motion/v/interpreting_motion_data 2024-06-21T18:55:31.273097146Z Interpreting motion data The same motion data can be presented in various ways, including dot (oil drop) diagrams, position-time tables, and position vs. time graphs. The slope of a position vs. time graph represents the object's velocity: A straight line (constant slope) means the object moved with constant velocity, and a curved line (changing slope) means the object accelerated. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/173ff128-6009-44d0-848c-3e7efb53454b_1280_720_base.png Interpreting motion data The same motion data can be presented in various ways, including dot (oil drop) diagrams, position-time tables, and position vs. time graphs. The slope of a position vs. time graph represents the object's velocity: A straight line (constant slope) means the object moved with constant velocity, and a curved line (changing slope) means the object accelerated. https://cdn.kastatic.org/ka-youtube-converted/-1xbgz26ZNs.mp4/-1xbgz26ZNs.mp4 606 Describing motion https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:kinematics/x0e04e0cb682fb793:speed-and-velocity/a/describing-motion 2026-06-30T17:40:47.272317428Z Learn and try: Describing motion Learn how to describe where an object is located and how it's moving. Analyze motion data using tables and graphs. Explore why reference frames and units are important when describing motion. article https://www.khanacademy.org/science/highschool-physics/x6679aa2c65c01e53:motion-and-forces/x6679aa2c65c01e53:describing-motion/e/understand-motion-variables 2026-05-22T02:50:56.444203687Z Understand: Motion variables Check your understanding of motion variables in this set of free practice questions. Emily Cizmas exercise https://www.khanacademy.org/science/highschool-physics/x6679aa2c65c01e53:motion-and-forces/x6679aa2c65c01e53:describing-motion/e/apply-constant-speed-motion 2026-05-22T02:50:56.444203687Z Apply: Constant speed motion Apply your knowledge of constant speed motion in this set of free practice questions. Emily Cizmas exercise https://www.khanacademy.org/science/highschool-physics/x6679aa2c65c01e53:motion-and-forces/x6679aa2c65c01e53:describing-motion/e/apply-accelerated-motion 2026-05-22T02:50:56.444203687Z Apply: Accelerated motion Apply your knowledge of accelerated motion in this set of free practice questions. Emily Cizmas exercise