Our Dynamic Universe Key Terms Flashcards
Scalar
A quantity fully described by it’s magnitude.
Vector
A quantity fully described by magnitude and direction.
Distance
How far an object has travelled from starting point to finishing point of a journey. It is a scalar quantity.
Displacement
- How far you are from your starting point.
- vector quantity
- given by area under velocity-time graph
Speed
The distance travelled per unit time. (scalar quantity)
Average speed
The total distance travelled by an object measured over the total time taken.
Velocity
The displacement per unit time. (vector quantity)
Acceleration
- The change in velocity per unit time
- vector quantity
- gradient of v-t graph
Friction
A force which opposes the motion of an object.
Balanced forces
when the forces acting on an object are equal in magnitude but opposite in direction.
Unbalanced forces
when the forces acting on an object are different in magnitude and different in direction.
Newton’s 1st Law
An object will remain at rest or move at a constant speed in a straight line unless acted on by an unbalanced force.
Newton’s 2nd Law
When the forces acting on an object are unbalanced, the object will accelerate in the direction of the unbalanced force.
Newton’s 3rd Law
Every action has an equal and opposite reaction.
Newton pairs
action and reaction forces for a specific situation involving Newton’s 3rd Law.
Tension
the pulling force of a string, cable or chain.
Free-fall
describes the movement of any object under the influence of gravity alone.
Terminal velocity
a constant speed reached when the upward force on the object (air resistance) is balanced by the downward force on the object (weight).
Weight
- the force due to gravity acting on an object
- vector
- measured in newtons
Work done
- a form of energy measured in joules
- describes the force applied to move an object a certain distance.
Gravitational potential energy
the energy stored by an object as a result of its vertical position above the surface of the Earth.
Kinetic energy
the energy possessed by a moving object
Law of Conservation of energy
Energy cannot be created or destroyed, but can change from one form to another.