3.2 Forces In Action Flashcards
what is a force
When a resultant force, F, acts on a body with mass m, the body will accelerate. The resultant force is related to mass and acceleration by the formula 𝐹=ma
define the newton
1kg = 1ms-2
What is Drag
An object moving through a fluid experiences a drag force acting on it. Drag is a frictional force that opposes motion.
What are the two most significant factors of drag
The two most significant factors are the speed of the object, and the object’s cross-sectional area
Relationship of drag and speed
Because drag is proportional to the square of the speed, the drag force will increase until it is equal in magnitude to the weight of the object
What is terminal velocity
when the force downwards = the drag force and can no longer accelerate
Moment of a force
The moment of a force can be defined as the magnitude of the force, multiplied by the perpendicular distance from the force to the pivot
what is a couple
A couple is a pair of forces, that have equal magnitude and opposite direction
What is a torque
The torque of a couple is defined as the product of the magnitude of one of the forces
What is the principle of moments
It is written as 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 density
is defined as the mass per unit volume in kgm-3
What is pressure
normal force exerted on a surface per unit cross sectional area in Nm-2
How would you find the height of the cyclinder
and as the height of the column is equal to the column’s volume divided by its cross-sectional area, h = V/A
What is Archimede’ 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. the weight is equal to the upthrust,
