Chapter 4 - Mechanics Flashcards
What is a moment?
the measurement of the perpendicular distance from the point of rotation to a force’s line of action. (The turning effect of a force.)
What is the equation for moments?
M=FD, Moment = Force x The perpendicular distance between a force and a pivot.
Name 3 vectors
displacement, velocity, force, acceleration, momentum
Name 3 scalar forces
Distance, Speed, Mass, Temperature, Time, Energy
What is the difference between scalar forces and vector forces
Scalar forces are force with no direction, Vectors are forces with both direction and magnetude
What is the resultant force of an object in equalibrium?
there is zero resultant force, if an object is in equilibrium all the forces acting on the object are balanced and cancel each other out.
What is the equation for weight?
Weight = mass x gravitational field strength
What is the definition of a couple?
A couple is a pair of forces of equal size which act parallel to each other but in opposite directions.
define the centre of mass
the single point that you can consider its whole weight to act through
Whats the difference between weight and mass
Mass is a scalar quantity and isnt dependant on the gravity acting upon it, whereas weight is a vector quantity that depends on the gravitational field strength
State the principle of moments
For an object to be in equilibrium the sum of clockwise moments must equal the sum of anticlockwise moments
If an object is in equilibrium it means the object is…
Not accelerating, so either,
Stationary
or moving at a constant velocity
What is Newtons 1st law of motion?
an objects velocity will not change unless a resultant force acts on an object.
What is newtons 2nd law of motion
Force = Mass x Acceleration, the acceleration a body experiances is directly proportional to the resultant force acting on it.
What is newtons 3rd law
If object B exerts a force on object A, then object A will exert an equal and opposite force of the same type on object B
