physics: Dynamics Flashcards
resultant force
ma
Newton’s 2nd law of motion
resultant force is proportional to mass * acceleration
inertia
a measure of how difficult it is to change the velocity of an object, or change its speed or direction. It is a measure of the mass of an object; a massive object has large inertia
weight
the force on an object caused by gravitational field acting on its mass
friction
the name for a resistive force when two surfaces are in contact and tending to slide over one another
drag. and how can it be reduced
drag acts to oppose the motion of the object; it acts in the opposite direction to the object’s velocity. It can be reduce by giving the object a streamlined shape.
contact force
the contact force always acts at right angles to the surface that produces it .
tension
this is force in a rope or a string when it is stretched. T = mg.. it is equal to the weight of the object
centre of gravity
the point where the entire weight of an object appears to act
uniform motion
the natural state of motion of an object - uniform velocity, constant speed and direction
Newton’s 1st law of motion
an object will remain at rest or in a state of uniform motion unless it is acted on by a resultant force.
resultant force
the single force that has the same effect as all of the forces acting on an object
terminal velocity
the maximum velocity reached by an object falling under gravity or accelerated by a constant force
resistive force
a backwards force in the opposite direction to movement caused by friction or some other viscous force
drag
a force that resists the movement of a body through a fluid
