# Kinematics: Solving Motion problems for Velocity, Acceleration, Distance.

## 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?