Physics Final Flashcards
Unit A, D, E, F, and J
Period
time to make one revolution (not quarter)
Calculate the speed of an object in UCM.
circumference/ period
Speed vs. velocity for UCM
Speed: constant
Velocity: magnitude is the same but the direction changes
reason for centripetal acceleration.
Centripetal acceleration: due to centripetal force (frictional gravitational, normal, or tension force); always towards the center
centripetal force.
Direction is always toward the center
Unbanked curve
Flat curve; static friction matters; represents the max speed a car can negotiate without slipping
slippy= kinetic
Banked Curve
Frictionless; force due to fNsinO
Satellite in Orbit
In order to stay in orbit, must operate at fixed speed
Centripetal force due to gravitational force
Work
the amount of energy to get an object from one position to another using a constant force
Scalar; Joules
KE
All objects that move; Joules and never negative; scalar
Total kinetic energy
+= moving faster
-= deacclerating
0= velocity is constant
gravitation PE
The energy an object has to its relative position
NC forces
Non-conservative forces: applied, normal, kinetic friction, tension and air resistance
When there is no conservative force Ef=E0
Impulse
how long an average force is exerted on an object N*s
Same direction as force; vector
Change in momentum
Momentum
how large of a response an object has to an impulse kg*m/s
Same direction as velocity; vector quantity
conservation of momentum
when momentum final = momentum initial
Elastic collisions
Total initial kinetic energy= total final kinetic energy
P0=Pf
Elastic collision
1D collision
V2=0
Inelastic collision:
: initial kinetic energy does not equal total final kinetic energy
Completely inelastic collisions:
inelastic & 2 objects stick together
Can only use conservation of momentum if the momentum is 0
Define center of maass
When you have 2 masses, the center of mass is the average location for the total mass from some point of reference
If total momentum is conserved, them vcm0=vcmf
Conductors
difficult for electrons to pass through
Wood, plastic and rubber
Insulators
electrons can easily move
Copper, Gold, Aluminum, Mercury, Silver
Conservation of charge
When the net charge of an isolated system remains constant
Charging by contact
When a negatively/ positively charged rod touches and uncharged metal sphere; rod is pulled away so charge stays in sphere
Discharge by connecting wire to laptop to ground (discharges when touches ground)
.By induction
When a negatively/positively charged rod touches a charged sphere; the similar charges in the sphere are repelled and the opposite are attracted
Wire is attached and the opposite charges are pushed out and escape
How do electric forces act on a particle?
Repulsive force: like charges
Attractive force: dissimilar forces
Electric Field:
measure intensity of the electric force at a location; electrostatic force experienced by a small test charge
1.Always point from + to -
2.Field lines originate from + and to -
3.Closer lines= stronger
4. # of lines leaving += mg of charge
Capacitators
electrical devices that store electrostatic energy.
Power
the rate at which work is done
Watt (Joule/Second)
