physics g10
first law of motion
an object continues to be in a state of rest, or of uniform velocity in a straight line as long as no external force acts upon it. Law of inertia
second law of motion
if there is a net force acting on an object, the object will experience an acceleration.
third law of motion
for every action, there is an equal and opposite reaction.
how to change from g to kg?
divide by 1000
how to change km to m?
times by 1000
change kmh to m/s
divide by 3.6
how to change cm to m
divide by 100
change mg to kg
mg-g-kg
how many seconds in an hour
3600
how to calculate distance
add all numbers together
how to calculate displacement
east - west, north minus south (order doesnt matter). put answer with direction next to it. ex) 2m[S]
distance graph
times the point of v and t. ex) v=3, t=5, delta x=15
what happens when velocity in a graph changes from positive to negative
the movement of the object switches directions
how does inertia apply to car accidents and neck injuries
it applies when the car gets rear ended bc your body wants to stay at rest, but the force pushed you backward, so your neck jerks quickly, and the headrests stop your head from flinging back
why does running in a zigzag away from an elephant help
higher mass, harder to accelerate
why are astronauts called weightless
they still have inertia/mass, but no gravity means no weight
net force in same direction
add them
net force in opposite direction
subtract them, write direction beside number
which units go where (delta x = v delta t)
X= m
V= m/s
T= s
which units go where (delta v = a delta t)
T= s
V= m/s
A= m/s squared
which units go where (f = ma)
f= N
m= kg
a= m/s squared
also find t and v
which units go where (p=mv)
P=kgm/s
M=kg
V=m/s
which units go where (pi + delta p= pf)
Pi= kgm/s
Delta P= kgm/s
Pf= kgm/s
m, vi, vf stay the usual ones