frictional forces and movement Flashcards
what is frictional force
a force that acts in the opposite direction to movement
what do fictional fore=ces always try to do
slow down moving objects
what is the first type of frictional force
friction - rubbing two surfaces together
what are the forces used for friction
push force
friction
what is the second form of frictional forces
air resistance
what is the third type of frictional force
water resistance
what are frictional forces also known as
drag
how does a skydiver gain speed
they gain speed by weight
what happens when there is more air resistance when a skydiver jumps
they are still gaining speed but air resistance is increasing
what happens when the parachute opens when a skydiver jumps
air resistance increases enormously when the parachute opens ans slows the skydiver down
what happens soon after the parachute opens
air resistance = weight and skdiver falls at a steady speed
what is moment
the turning effect of a force
whats is a pivot
the point around which rotation happens
what is the equation to calculate moment
M = F x D
what does M stand for in the equation to calculate moment
moment in newton metres, Nm
what does F stand for in the equation to calculate moment
F stands for force in newtons, N
what does the D stand for in the equation to calculate moment
D stands for the perpendicular distance from the pivot in metres,M
if moments aren’t balanced what direction does the object move in
objects turn in the direction of the bigger moment
what happens if moments are balanced
no change in movements
