PHY C3: Mass and Linear Momentum

What is Kinematics?

The study of how objects move.

What is Mechanics?

The study of the motion of objects, with associated concepts of force and energy.

What are the two parts of Mechanics?

Kinematics (how objects move) and Dynamics (force and why objects move).

What are the three types of motion?

Translational, rotational, and vibrational.

What is a Particle (in motion studies)?

A point-like object with mass but no size. Used as a model for objects where positions refer to their centres of mass.

What is Rectilinear Motion?

Motion in one dimension or motion in a straight line.

What is a Frame of Reference?

The point or system relative to which measurements of distance or speed are made. Assumed to be a stationary observer on Earth unless specified.

How is a Frame of Reference represented?

By a coordinate system.

How are axes chosen for motion in a plane?

As a pair of mutually perpendicular axes (x- and y- axes), with the origin usually as the point of launch.

What is Distance (x)? (Scalar Quantity)

The total length of path an object travels.

What is the SI unit for Distance?

Metre (m).

What is Displacement (s)? (Vector Quantity)

The distance moved in a specified direction from a reference point.

What is the SI unit for Displacement?

Metre (m).

What is Speed (v)? (Scalar Quantity)

The instantaneous rate of change of distance travelled with respect to time (v = dx/dt).

What is the SI unit for Speed?

Metre per second (m s⁻¹).

What is Velocity (v)? (Vector Quantity)

The instantaneous rate of change of displacement with respect to time (v = ds/dt).

What is the SI unit for Velocity?

Metre per second (m s⁻¹).

What is Average Speed?

The total distance travelled over total time taken.

What is Average Velocity?

The change in displacement over total time taken.

What is Instantaneous Acceleration (a)? (Vector Quantity)

The rate of change of velocity with respect to time (a = dv/dt).

What is the SI unit for Acceleration?

Metre per second squared (m s⁻²).

What is Average Acceleration?

The change in velocity over time taken.