Forces pt3 Flashcards
What Newton’s second law?
The acceleration of an object is proportional to the resultant force acting on the object and inversely proportional to the mass of the object.
What is the acceleration?
a measure of how quickly an object speeds up, slows down or change direction
What is the equation that connects force mass and acceleration?
Force = mass x acceleration
The equation of acceleration
acceleration = change in velocity/ time taken
What is inertia?
the tendency for objects to continue in the same state of motion
it is how difficult it is to change the velocity of an object
What is a measure of inertia?
mass
How is the inertial mass found?
(whats the equation)
m = f/a
The larger the mass, the _____ the force needed to change the velocity
bigger
Describe what terminal velocity is
When an object falls through a fluid :
1) At first the object accelerates due to the force of gravity
2) As it speeds up, the resistive forces increases
3) The resultant force reaches zero when the resistive forces balance the force of gravity
At this point, the object will fall at a steady speed = terminal velocity
What is Newton’s Third Law?
Whenever two objects interact, the forces they exert on each other are equal and opposite.
(Every action has an equal and opposite reaction)
What is the equation for momentum?
momentum = mass x velocity
p = mv
When does a change in momentum occur?
When a force acts on an object that is moving, or able to move
What type of quantity is momentum?
vector
What is the conservation of momentum?
In a closed system, the total momentum before an event is equal to the total momentum after the event.
Describe free-fall acceleration
the objects weight acts as a downwards force and aerodynamic drag acts in the opposite direction.
As the object starts falling, the object’s weight acting downwards is greater tha the aerodynamic drag = accelerates downwards
as the object accelerates the magnitude of aerodynamic drag increases
Drag increases until it is equal to the object’s weight= no result force acting on the object = moves at a constant velocty (terminal velocity)
