4.1-4.8 Forces in Action Quizlet Cards Flashcards
What is the centre of mass of an object?
The point at which the weight can be assumed to act.
What does the weight of an object depend on?
It’s mass and the gravitational field strength (W=mg)
What is a free-body diagram?
It is a diagram showing the set of forces acting on a single object.
What is weight?
The force due to gravity that acts through an objects centre of mass.
What is friction?
The force that acts between two surfaces in contact to oppose motion.
What is drag?
The resistive force that acts on an object moving through a fluid
What is tension?
The force within a stretched object such as a cable or rope.
What is upthrust?
The upward buoyant force that acts on an object in a fluid.
What is a normal contact force?
A force that acts perpendicular to a surface when an object rests on it.
How do you calculate the component of weight down a slope?
W sin (θ) where θ is the angle between the slope and horizontal.
How do you calculate the component of weight acting perpendicular to a slope?
W cos (θ) where θ is the angle between the slope and horizontal.
What are the key factors in determining the magnitude of drag force acting on an object in a fluid?
Speed and cross-sectional area
What is terminal velocity?
The maximum speed reached by a falling object when drag and weight are equal.
What is a moment?
The turning effect produced by a force.
What units do moments have?
Nm
