Forces Flashcards
Speed and Distance are _____ quantities.
Fill in the blank:
Scalar
What information does scalar quantities only contain?
magnitude(size)
Velocity and Displacement are ____ quantities.
Fill in the blanks:
vector
what information do vectors contain?
magnitude and direction
Give 5 examples of scalers:
mass time speed distance length
Give 5 examples of vectors:
momentum force velocity displacement acceleration
where do arrows start on free body force diagrams?
on the object
what do free body force diagrams show?
forces acting on a single object (body)
what is newton’s third law?
Every action has its equal and opposite reaction.
why do balloons go forward when let go?
- the balloon exerts a PUSHING FORCE making air go backwards
- the air exerts a BACKWARDS FORCE making the balloon go forward.
what is newton’s first law?
- if forced on an object are balanced: if - it’s stationary it stays stationary.
- if it is moving it will continue moving at a steady pace in a straight line.
- this means if forces on an object are balanced, the velocity stays the same.
what are the three effects of unbalanced (resultant) force on an object?
- changes the objects speed
- changes the objects direction
- changes the objects shape
the further away a force is from the pivot, the ____ effect it has.
Fill in the blank:
more
what is the equation for moment?
moment= force * distance
what are gears?
-gears are rotating wheels with teeth (“cogs”) that interlock with another wheel hence they act like levers
what are gears used to transmit (and often multiply)?
rotational forces
how do gears work?
- turning force is applied to one of the wheels
- interlocking wheel turns the adjacent wheel in the opposite direction
- teeth/cogs are there to prevent the wheels from slipping
how do these gears multiply force?
Gear 1- 12 teeth
Gear 2- 24 teeth
-a wheel with more teeth (which are the same size)
-in the diagram, the bigger wheel is moving half as fast as the smaller wheel
-but the moment of the turning point will
be twice as big (due to the radius being 1:2)
what is the centre of mass?
the centre of mass of an object is the point which the mass can be thought as being concentrated.
the centre of mass of an object is the point through which a single force on the body has no ________ effect.
the centre of mass of an object is the point about which its mass is ______ distributed.
Fill in the blanks:
turning
evenly
what does an object need to have to be stable?
a low centre of mass
wide bass
what is the equation for the principle of moment?
w1d1=w2d2
