Forces Flashcards
What is a scalar quantity ?
quantities that only have MAGNITUDE
What is a vector quantity?
Quantity that have both MAGNITUDE and DIRECTION
What is weight and mass?
weight: force acting on an object due to gravitational attraction.
MASS: amount of matter in object
weight equn?
W=m/g
What is resultant force? and what does it determine?
single force that describes all forces operating on an object
determines:
- direction of objects
- magnitude of force on object
work done equn?
w=f x d
what is newton’s first law?
An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force
what is newton’s second law?
the acceleration of object is proportional to the resultant force acting upon it (and inversely proportional to object’s mass)
what is newton’s third law?
When two objects interact the forces they exert on each other are equal and opposite
explain the changing motion of a skydiver in terms of forces acting on a skydiver when falling?
air resistance is lower than force of weight - ACCELERATES
as acceleration increases, air resistance increases
so weight/gravity = air resistance
he reaches terminal velocity
What is a force
A push or pull that acts on an object due to the interaction with another object
3 eg of contact forces
Tension, friction, air resistance
3 eg non contact forces
Gravitational, electrostatic, magnetic
