Forces in action Flashcards
(15 cards)
What is drag?
The resistive force on an object travelling through a fluid
What is friction?
The force that arises when two surfaces rub against each other
What is tension?
The force within a stretched cable or rope
What is up-thrust?
The upward buoyancy force acting on an object when it is in a fluid
What is the normal contact force?
The force arising when an object rests against another object
acting at a 90° angle to the plane of contact
What is terminal velcoity?
The maximum velocity an object can reach during freefall
What are the conditions for terminal velocity?
The weight of the object = the drag force acting on the object
What is a moment?
The magnitude of the force, multiplied by the perpendicular distance from the force to the pivot
What is a couple?
A pair of forces, that have equal magnitude and opposite direction
What is torque?
The product of the magnitude of one of the forces, and the perpendicular separation between the forces
What is the principle of moments?
For a body in equilibrium, the sum of the clockwise moments about any point is equal to the sum of the anticlockwise moments about the same point
What is centre of gravity?
The point where the entire weight of the object appears to act
How can you determine the centre of gravity of an object?
Suspend the object from any point
Use a plumb line to draw a line vertically down from this point
Repeat
Intersection is where centre of gravity is
What is Archimedes’ principle?
The 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 is the principle of floatation?
When an object floats on a fluid the buoyant force that acts on the object is equal to the weight of the object
