- length of a particular path from A to B,
- a scalar quantity
Distance
- distance travelled but with associated direction
- a vector quantity
Displacement
Change in position (∆x) divided by time for change (∆t)
Velocity
- The rate of change of velocity
- a vector quantity
Acceleration
A body continues at rest, or at constant velocity, unless acted on by a force.
Newton’s First Law
When a force is applied to an object the acceleration is proportional to the force applied and the constant of proportionality is the mass of the object.
Newton’s Second Law
Which law establishes F=ma?
Newton’s second law
To every action there is an equal and opposite reaction.
Newton’s third law
Centripetal acceleration
The acceleration pointing towards the center of circular motion
An object is in ____ equilibrium if the forces acting on it are such that it remains stationary.
static
____ equilibrium: object returns to equilibrium after small displacement
stable
____ equilibrium: object does not return to equilibrium after small displacement
unstable
Torque is defined as
Force times distance
Work is defined as
Force times distance
We say that friction is a ____ force; it removes mechanical energy (KE +PE) from a system.
dissipative
Forces which do not remove mechanical energy are called ____ forces.
conservative
Power is defined as
Work / time
In what type of collision is
- Momentum is conserved
- Kinetic energy is also conserved
Elastic
In what type of collision is
- Momentum is conserved
- Kinetic energy is not conserved – some
energy converted into thermal energy, sound
or used to deform the objects.
Inelastic
In what type of collision do
- The colliding objects stick together after the collision
sticky inelastic collision
Atoms with same number of protons (Z), but different number of neutrons, thus different mass number (A)
Isotopes
The four fundamental forces
- Gravity
- Electromagnetism
- Strong nuclear force
- Weak nuclear force
The ____ nuclear force is responsible for neutron decay, leading to beta-particle emission.
weak
____ particles are a fast moving electrons, lower in mass and more penetrating.
Beta
