2.4 Kinematics & Kinetics

What is Kinematics ?

The study of motion

• focuses on the spatial and temporal representations of HOW particles, bodies, or systems move

• describes the geometry of motion

• does not address forces as the cause of motion

What is Kinetics ?

The study of motions caused by forces

It analyzes motions resulting from the effects of forces that are not in equilibrium with each other

What is the difference between the distance traveled and the displacement ?

distance travelled : the full path that the body has traveled between two positions

displacement : how far the body is from its starting position

What is the formula for the velocity ?

How can you determine the displacement using the velocity-time diagram ?

It’s the area under the curve, as velocity represents the time derivative of the displacement

For uniform motion at constant velocity, the displacement is calculated as the area of a rectangle:

What is the formula for a constant acceleration ?

What relationship can you establish between acceleration, velocity and displacement ?

What is the difference between velocity and speed ?

velocity is a vector (magnitude + direction) and depends on displacement

speed is a scalar (only magnitude, no direction).