IB Physics - Kinematics & Work, Energy, and Power

Distance

Total length of the path traveled by an object

Scalar

(m)

Displacement

Final position - initial position

Vector

(m)

Vector

Magnitude + Direction

Scalar

Magnitude

Speed

How fast the distance of an object is changing

Scalar

(m/s)

Velocity

How fast and in which direction the distance of an object in changing

Vector

(m/s)

Average Speed Formula

total distance / total time

Average Velocity Formula

total displacement / total time

Acceleration

How fast the velocity of an object is changing

Vector

(m/s²)

When the acceleration and velocity have the same sign (+ or -), the object is

Speeding up

When the acceleration and velocity have different signs (+ and -), the object is

Slowing down

Newton’s 1st Law / Law of Inertia

An object at rest will stay at rest, and an object in motion will stay in the same motion, unless acted upon an unbalanced force

Newton’s 2nd Law

F=ma

Instantaneous Speed/Velocity

The speed/velocity at a particular point in time

Instantaneous Velocity is equal to the

The slope of a point on a position v. time graph

Unit of Work

Joules (J) / kg⋅(m/s)²

Work is equal to the

change of kinetic energy

When the speed of an object is slowing down

Work is negative

When the speed of an object is speeding up

Work is positive

Mechanical Energy

Kinetic + Potential Energy

Power

Rate of which work is done

Rate of which energy is transferred

Work / Time

Units of Power

Joules / Seconds

Watts

Conservation of Potential and Kinematic Energy

Ke1 + Pe1 = Ke2 + Pe2

Internal Energy of a Real Gas

Sum of kinetic and potential energy of molecules