Presentation on theme: "Kinematics: Solving Motion problems for Velocity, Acceleration, Distance."— Presentation transcript:
Kinematics: Solving Motion problems for Velocity, Acceleration, Distance
Kinematics The problems we’ll do involve either constant velocity or velocity which is changing in a uniform way. In other words, only problems with no acceleration or constant acceleration. I encourage you to always make a graph of the motion to help you visualize (and solve) the problem. When starting the problems, sometimes it’s not obvious which “equation” to use. If you are not sure, start somewhere and if that doesn’t work, look at another relationship.
Kinematics Velocity (ave) = Total Distance/total time or V ave = d/t Acceleration = change in Vel / change in time, or A = (V 2 – V 1 ) / t When something is accelerating, then V ave = (V 1 + V 2 ) / 2
Kinematics General Problem Solving Strategy Draw a graph of the problem, usually this is a velocity vs. time graph, including the details of what you know on the graph Write down all the known values and also what you are looking for. Solve using the Kinematic equations OR the graph On a Vel vs. Time graph, the area of the graph = total distance traveled.
Kinematics example: A raven flies at 10 m/s for 7 sec. How far does it fly (this is simple, but illustrates a point about the graph)
Another Kinematics Example with acceleration A Barracuda accelerates from rest at an accel of 4 m/s/s for 6 sec. a) what is the final velocity? b) How far does it swim?
Another example….. You borrow your brothers Ferrari and are driving at 80 m/s when you see a cop and need to slow to 20 m/s. This requires 4 seconds. a) What is your acceleration? And b) how far did you go?