Mechanics Flashcards
What is the equation of a turning moment?
Turning moment = force applied x perpendicular distance from the pivot.
(M= F x d)
What is a scalar quantity?
A measurement which has size only.
What is a vector quantity?
A measurement which has size and direction.
Name four examples of a scalar quantity.
Speed, Distance, Energy and Time.
Name four examples of a vector quantity.
Force, Displacement, Velocity and Acceleration.
Example question: What is greater during a parachute fall, the drag produced by the parachute or the gravity causing the fall?
Neither, they are both equal due to the drag and gravity being balanced causing a constant velocity/speed when falling, as stated by Newtons first law of motion.
What is Newtons first law of motion?
When no force acts, or two balanced forces act on an object, that object will remain at rest or continue to move at a constant speed.
What is a pivot?
The point about which an object rotates.
What must be equal for an object to be in equilibrium?
Clockwise moments = anti-clockwise moments
meaning sum of the forces and sum of the turning moments are equal
What is the centre of mass?
Centre of mass is the average location for an object; where the forces of the object are equally balanced.
What is a ‘couple’?
When a pair of forces is applied in parallel to eachother but in opposite direction to provide a turning effect but no translational movement, such as when using a steering wheel with two hands.
What is ‘resolving a vector’?
When splitting up a diagonal vector into two seperate mutually perpendicular components which add up to the original vector (use of pythagoras theorem).
