Kinematics

• Velocity has both magnitude (speed) and direction
• The velocity is the rate at which an object changes position.
• Acceleration is the rate at which velocity changes with time.
• The SI unit for acceleration is m/s^2
• Average speed = total distance travelled / total time taken
• Displacement is the change in position from one point to another, measured as distance along a straight line between two points.
• Instantaneous speed = speed at any given moment in time
• Formula for Average velocity is (total displacement)/(total time)
• average speed = (total distance)/(total time)
• instantaneous velocity in 1 dimension $v =$$\lim_{{\Delta t \to 0}} \frac{{\Delta x}}{{\Delta t}}$
• the magnitudes of instantaneous speed and instantaneous velocity are always the same
• Instantaneous velocity is the average velocity over an infinitesimally small period of time
• If an object moves at a uniform velocity during a time interval, it’s instantaneous velocity at any moment is the same as its average velocity
• The slope of a position-time graph gives us the velocity of an object.
• formula of average acceleration$a_{avg} =$$\frac{\Delta v}{\Delta t}$
• To represent acceleration in one dimension we put + or - to specify the direction on a position time graph
• Formula for instantaneous acceleration $a =$$\lim_{\Delta t \to 0} \frac{\Delta v}{\Delta t}$
• Acceleration tells us how quick the velocity changes, and velocity tells us how quickly the position changes