Chapter 5.2: Force, mass and acceleration Flashcards
State Newtown’s First Law
An object remains at rest or in constant motion in a straight line unless acted on by a net unbalanced force.
Define force
An influence tending to change the motion of a body or produce motion or stress in a stationary body.
State Newtown’s Second Law
The acceleration of an object is directly related to the magnitude and direction of the force acting on the object, and inversely related to the mass of the object: F = ma.
State Newtown’s Third Law
For every action force, there is an equal and opposite reaction force.
State the name of a pair of forces that obey Newtown’s Third Law
Action-reaction forces
Define inertia
A property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force.
Define net force
The net force is the vector sum of forces acting on a particle or object
Define force diagrams
A diagrammatic representation of a single body or a subsystem of bodies isolated from its surroundings showing all the forces acting on it.
Define vector diagrams
A diagrammatic representation of a single body or subsystem of bodies that depict the direction and relative magnitude of a vector quantity with vector arrows
In which direction will a passenger go if the driver suddenly brakes and why?
The passenger will lurch forward since the inertia of the passenger makes it want to stay in its state of rest
In which direction will a passenger go if the driver accelerates suddenly and why?
The passenger will lean back since the inertia of the passenger makes it want to stay in its state of rest
Compare force diagrams with vector diagrams
Force diagrams illustrate the forces acting on the object in a similar manner to reality, on the other hand, the vector diagram transforms the forces into a shape to illustrate the net force
Describe the function of a vector diagram
A vector diagram depicts the net force of a single body or subsystem of bodies
Define mass
The amount of matter in an object
Define weight
The force of gravity on objects
Identify the units used to measure mass
Newtowns (N)
Identify the units used to measure weight
kilograms (kg)
Identify the units used to measure force
Newtowns (N)
How can an object accelerate without changing speed?
An object can accelerate by changing direction
