Flashcards in physics Deck (18)
Loading flashcards...
1
what is velocity
- rate of change of displacement (ms-1)
2
what is acceleration
- measure of how quickly velocity changes (ms-2)
3
what is projectile motion
- a parabolic path traveled by an object projected into the air
- the object’s motion is influenced by; initial launch speed, launch angle and acceleration due to gravity
4
what is centripetal motion / force
- M: motion in a circular path due to the action of centripetal force
- F: force on an object directed to the centre of a circular path that keeps the object on the path
5
what are newtons three laws of motion
1. an object will continue in a state of inertia unless acted upon by an unbalanced external force
2. acceleration of an object is directly proportional to the net force acting on it and inversely proportional to the mass (F = (m)(a)
3. every force has an equal and opposite reaction force
6
what is universal gravitation
- every object exerts a gravitational force on every other object
- force = directly proportional to mass (increase mass = increase force)
- force = inversely proportional to distance (increase distance = decrease force)
- distance has more of an impact than weight
- F = Gm1m2 / r^2
7
what is kinetic energy vs potential energy
- K: mechanical energy, object in motion, how quickly its moving
- P: mechanical energy, potential to do work, 0 at ground
8
what is archimedes principle
- the buoyant force acting on a substance in a fluid at rest is equal to the weight of the fluid displaced by the substance
9
what is the combined gas law
- under constant temperature (in kelvins = celsius +273), pressure and volume are constant
- as pressure increases the volume decreases
- P1V1 / T1 = P2V2 / T2
10
what is the law of conservation of electric charge
- net amount of electric charge produced is always zero, net electric charge can not be created or destroyed
11
what is coloumb's law
- interaction between electrically charged objects
- like charges repel and opposite charges attract
- repel / attract proportional to the charge
12
what is a parallel vs series circuit
- P: two or more resistors connected across two points, Req = 1/R1 + 1/R2 + 1/R3, parallel lines in-between, current = changes (I = I1 + I1 + I3), same voltage, I increases = R decreases
- S: two or more resistors connected one after the other, Req = R1 + R2 + R3, circle, current = same, differing voltages (V = V1 + V2 + V3)
13
what is wavelength, amplitude and frequency and how are they related
- λ: wavelength, metres, between peak of one wave and corresponding peak of another or two corresponding points
- a: maximum height of a crest / trough relative to normal level
- f: number of oscillations passing a given point per second (number of crests)
- v (speed) = (f)(λ)
14
what is reflection
- wave hits an object and bounces off of it
- beam striking surface will reflect with an angle equal to that of the incident beam
- diffuse reflection: rough surface, different directions of reflection
- perfect reflection: incident angle = reflected angle
- total internal reflection: angle of incidence exceeds the critical angle
15
what is refraction
- deflection of a wave passing from one medium (air) into another (glass), light bends towards normal
- change in medium / speed (refractive index)
- incident ray angle (between ray and normal)
- refracted ray angle (between ray and normal)
- critical angle: angle of incidence gives an angle of refraction of 90° [sin𝜃c = (n2 / n1)sin90]
16
what is snells law
- relationship between angles of incidence (Li) and refraction (Lr)
- n1sin𝜃1 = n2sin𝜃2
- n1 (reflection index of first material), 𝜃1 (angle of insert), n2 (refraction index of second material), 𝜃2 (refraction angle)
17
what is transverse / longitudinal wave:
- t: particles of medium vibrate up and down in direction perpendicular to that of travel
- l: vibration of particles along the direction of the waves motion
18
