P8 - Forces in Balance (PAPER 2) Flashcards
what is displacement
Distance from the start
what is a vector quantity
a physical quantity which has magnitude and direction
what is a scalar quantity
a quantity which has magnitude but no direction
How are vector quantities displayed
with an arrow pointing in the correct direction, of the length in proportion of the magnitude
what are three things that forces do
- change an object’s shape
- change an object’s motion
- change an object’s state of rest
What is the unit for force
Newtons (N)
What is a contact force
a force that only acts on objects when they touch each other
what is a non-contact force
a force that can act on an object without contact
what is a resultant force
a single force that has the same effect as all the forces acting on an object
what happens if the resultant force on an object is zero
the object stays at rest or at th same speed and direction
what is a free body force diagram
a diagram of an object that shows the forces acing upon it
what is the centre of mass of an object
the point where its mass can be thought of as being concentrated
where is the centre of mass of an object suspended from a fixed point
directly below the point of suspension
what is the parallelogram of forces
a scale diagram of two force vectors
what is the parallelogram of forces used for
to find the resultant of two forces that do not act along the same line
