P8 Flashcards
What is a vector quantity?
Physical quantities that have direction and size are called vectors.
What is a scalar quantity
Physical quantities that have size, but no specfic direction are called scalars.
What is the difference between displacement and distance?
Displacement is the distance from A to B in a straight line but distance is actually how far you travelled along your route. DISTANCE WITHOUT CHANGE OF DIRECTION IS CALLED DISPLACEMENT.
What is Newtons 3rd law
When two objects interact with each other, they exert equal and opposite forces on each other.
What is a contact force? Examples?
If two objects must touch each other to interact, the forces are called contact forces. Examples: friction,air resistance and stretching forces.
Whats a non-contact force? Examples?
A non-contact force is forces that act between two objects that are not physically touching each other. Examples include magnetic force, electrostatic force, and the force of gravity.
What is friction
When two surfaces slide past each other, the interaction between them produces a force of friction. Friction is a force that opposes motion.
What is the resultant force
The direction in which the object will move as a result of all of the forces.
Whats Newtons law 1?
If the forces acting on an object are balanced, the resultant force on the object is 0.
If the object is moving, it will keep moving at the same speed.
If the object is at rest, it will stay at rest.
Whats an unbalanced force?
When the resultant force on an object is not 0, the forces acting on it are unbalaced
Whats a free body diagram?
Shows the forces acting on an pbject without any other object or other forces shown.
Whats a moment
The turning effect of the force.
Whats a lever
Levers act as force multipliers becuase effort moves a much bigger load.
P8.5 needed
Whats the principle of moments
when a body is balanced, the total clockwise moment about a point equals the total anticlockwise moment about the same point.
