Mechanics Flashcards
(21 cards)
μm
1x10^-6
Gm
1x10^9
Moment formula
moment = perpendicular force x distance
Centre of gravity
where the weight on all sides is equal and there is no moment
Centre of mass
the mean position of the mass of an object
When is the object in equilibrium?
when the total clockwise moment equals the total anticlockwise moment
weight of object
= (weightxdistance)/distance to centre of gravity
Work done
W = Fdcosθ
Catapult firing object.
a. Formula for how fast on release?
b. Formula for how high it gets?
a. v=√(kx^2 /m)
b. h = v^2/2g
Force from momentum
F = (mv-mu)/t
Formula used for recoil
P = mv
Difference between vector and scalar
scalar is magnitude only, whereas vector have magnitude and direction
base unit of the amount of substance
mole (mol)
base unit of temperature
kelvin (K)
Derive the unit of force
F = ma N = kg x ms^-2 N = Kgms^-2
Derive the unit of work done
W = Fd J = Kgms^-2 x m J = Kgm^2s^-2
Suvat equations
v = u + at s = ut + 0.5at^2 v^2 = u^2 + 2as s = 0.5(u+v)t
Newtons first law
an object will continue to move with uniform velocity unless acted upon by a resultant external force
Newtons second law
F = ma
Newtons third law
If object A exerts a force on object B, then object B exerts an equal but opposite force on object A
Newtons pairs
Same type of force
Same magnitude
Opposite direction
Acting on different objects
