Physics Unit 1 and 2 Flashcards
Independent variable
Changed by experimenter. The manipulated variable
Dependent variable
Measured; responding variable
What is accurate?
A true and correct value
What is precise?
Measures are fairly close together/clustered together
3 sources of error
1) Limited precision of measuring devices
2) Assumption in experimental procedure
3) Environmental factors that changed
7 Base SI Units (and what they measure)
- Meter (length)
- Kilogram (mass)
- Time (seconds) (3 main ones)
- Kelvin (temp)
- Mole (amount of matter)
- Ampere (electric current)
- Candela (luminous intensity)
6 Derived Units (and what they measure)
- Velocity (m/s)
- Acceleration (m/s/s)
- Momentum (kg/m/s)
- Force (kg m/s^2) –> Newton (N)
- Energy/work -> Nm->Joule (J)
- Power->J/s-> Watt (W)
What is scalar?
Magnitude only
Ex. Mass, length and time
What is vector?
Magnitude and direction
Ex. Force, velocity, acceleration
1st Law of Thermodynamics
Matter cannot be made or destroyed, it may only change forms
2nd Law of Thermodynamics
The amount of useful work energy can do decreases over time; the entropy (disorderliness) of a system always decreases with time)
3rd Law of Thermodynamics
Absolute zero is impossible to attain
Since energy is matter removing all energy destroys matter
5 forms of energy
Motion (mechanical ex. sound), Heat, Electromagnetic Radiation, Chemical and Nuclear
If a system is at equilibrium what does that mean?
All forces acting on it are balanced and therefore the motion doesn’t change
Static equilibirum
At rest
Dynamic equilibrium
Constant speed
Net force of an object at rest
0N
Sum of all forces on an object in static equilibrium
0
What is inertia?
The tendency for matter at rest to stay at rest and for matter in motion to stay in motion unless acted upon by an outside (unbalanced) force \
More mater equals….
More inertia
Object stays in equilibrium UNLESS…
Acted on by an unbalanced force
What is displacement?
Distance and direction
Distance: what does it measure? What quantity?
How far; Scalar (magnitude)
Displacement: what does it measure? What quantity?
How far and in what direction; Vector (Magnitude and direction)
Speed equation
d/t (scalar)
Velocity equation
displacement/time (vector)
Acceleration equation
change in velocity/time
Parallelogram rule: shortest distance? Fastest distance?
The one that’s perpendicular; the longer travelled distance
