Week 1 Flashcards
nano
n
10-9
micro
μ
10-6
mili
10-3
kilo
k
103
mega
M
106
giga
G
109
accuracy
how close a given measurement to a given standard
precision
reproducibility of a measurement, not necessarily related to the accuracy
Newton’s 1st Law:
Any object continues at rest, or at constant velocity, unless an external F acts on it
essentially, F is anything that is measurable and causes a change in the motion of an object
Newton’s 2nd Law:
External force gives an object an acceleration. The acceleration produced is proportional to the force applied, and the constant of proportionality is the mass.
F=mα
N = kg*m/s^2
Newton’s 3rd Law:
Fs come in pairs: f/ every F applied TO the body, there is a F applied BY that body
!action F & reaction F are acting on diff objects!
friction -
F directed along the surface, opposite the direction of the intended motion
Normal F
perpendicular component of the contact Force b/w 2 objects in physical contact w/ each other
statics
study of F in equilibrium, study of bodies which are not moving
positive torque -
motion in counter-clockwise direction (ccw)
negative torque -
motion in clockwise direction (cw)
a system is said to be in equilibrium when:
net F of that system is 0 and net torque of the system is 0
stable equilibrium:
system will return to equilibrium after a small displacement
unstable equilibrium
system will not return to equilibrium after a small displacement
for a system in static equilibrium all torques:
are balanced => no net torque
Principle of moments:
at equilibrium the sum of cw moments = ccw moments
ΣFcwdcw = ΣFccwdccw
1st class lever:
fulcrum in the middle, Work/Load & Force act on opposite sides in the same direction
2nd class lever
W(load) in the middle
ex: standing on tip toes
3rd class lever
F(muscle effort) in the middle
distance an object travels -
length of the path that the object took in traveling from one place to another, scalar
Displacement
s the distance travelled, but with a direction associated, vector
average velocity
displacement divided by the elapsed time, vector
Acceleration
how rapidly the velocity of an object is changing, defined as the change in velocity divided by the time taken to make this change, vector
Is torque a force?
No, it’s a moment
torque -
physical quantity which causes an object to begin to rotate or move in a circle or to change its rate of rotation
The amount of turning produced by the force applied to a rod will depend
- on the magnitude of the force (F) and
- the length of the rod (d)
𝝉 = 𝐅d
centre of gravity -
a point where all weight of an object acts
centre of mass
point at which the total mass of a body may be considered to be concentrated (for many purposes) in analysing its motion
