forces and action Flashcards
describe what happens when a resultant force f acts on a body with mass m
body will accelerate in the direction of the resultant force
f = ma
what is drag
object moving through fluid experiences a drag force acting on it, it is a frictional force that opposes motion
terminal velocity
when the forces acting on the falling object become balanced so resultant force is 0, the acceleration becomes 0 and moving at maximum velocity
principle of moments
sum of clockwise moments is equal to the sum of anticlockwise moments
moment
force by perpendicular distance , turning force
couple
a pair of equal and opposite coplanar forces that have equal magnitude and opposite direction, applied parallel to body
density
mass per unit volume
pressure
normal force exerted on surface per unit area
what is the force that an object submerged in a fluid experiences
upthrust as pressure at the bottom surface is greater than it is at the top of the surface
archimedes principle
upthrust exerted on a body immersed in fluid whether partially or fully submerged is equal to the weight of the fluid that the body displaces
what are the factors that affect drag for an object travelling through air
speed of the object, objects cross sectional area, the properties The object is falling through, drag is proportional to the square of the speed of the object
newton
the force that will give a mass of 1kg an acceleration of 1N
motion of objects fallen in a uniform gravitational field in the presence of drag
- initially when the object starts falling the force of gravity is greater than the drag force so the object accelerates downwards
- as gains speed the drag increases
- eventually the drag will equal the weight and the object will be falling with terminal velocity
torque of a couple
product of the magnitude of one of the forces, and the
perpendicular separation between the forces. This is equal to the total moment of the couple
