Mechanics Flashcards
How do you find the force acting down the slope of an object?
m x g x sin(angle)
What is a moment / torque?
The turning effect of a force.
Moment = Force x Distance (perpendicular to line of action of the force)
What is a couple?
Pair of forces, equal in magnitude and opposite direction, acting parallel to one another, but not along the same line.
What is terminal velocity?
When air resistance and the weight of a falling object are equal. No resultant force.
What is the centre of gravity of an object?
A point where the entire weight of the object seems to act.
What is the centre of mass of an object?
A point where the entire mass seems to be concentrated.
What is the principle of moments?
For an object in equilibrium, the sums of the clockwise and anticlockwise moments are equal about any pivot.
What is tilting?
The moment of the force applied about the pivot is greater than the moment of the weight about the pivot.
What is toppling?
Line of action of the weight passes to the other side of the pivot.
What is Newton’s 1st Law?
An object will remain at rest or constant velocity in a straight line unless acted upon by a resultant / net force.
What is Newton’s 2nd Law?
The rate of change of momentum of an object is directly proportional to the force producing it.
F = ma
What is Newton’s 3rd Law?
If an object A exerts a force on object B, then object B exerts a force on object A which is equal in magnitude, opposite in direction and of the same type.
What is power?
The rate at which work is done.
What is momentum?
Momentum = mass x velocity
What is the principle of conservation of momentum?
The total momentum before = the total momentum after.
