Speed and Velocity

Kinematics

In this course, Professor Derek Raine (University of Leicester) explores kinematics, which is the motion of objects without considering the forces that cause them to move. In the first mini-lecture, we discuss speed and velocity, looking in particular at average speed and graphical representations. In the second mini-lecture, we turn towards acceleration, where we seek to understand the rate at which objects fall under gravity and derive useful equations for systems experiencing constant acceleration. The third mini-lecture includes a discussion of graphical representations of distance, speed, and time, followed by an example that ties together the concepts learned so far. In the fourth mini-lecture, we explore gravity and seek to understand why all bodies, regardless of mass, fall with the same acceleration under gravity (the universality of freefall). In the fifth mini-lecture, we introduce projectile motion, which is the motion of a projected object that moves along a curved path under the action of gravity only.

Speed and Velocity

In this mini-lecture, we discuss speed and velocity, focusing in particular on: (i) examples of familiar speeds; (ii) average speed; (iii) the difference between speed (magnitude of rate of change of distance with respect to time) and velocity (speed with specified direction); and (iv) a graph of linear distance vs. time and the associated constant speed vs. time graph, where we see that the speed can be determined from the slope of the distance vs. time graph and that the area under the curve of the speed vs. time graph is the distance travelled.