Physics 2020 Exam 4 Constants and Formulae

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1 Physics 2020 Exam 4 Constants and Formulae Useful Constants k e = Nm 2 /C 2 ɛ = C 2 /(N m 2 ) µ = 4π 10 7 T m/a e = C G = Nm 2 /kg 2 h = Js h = h/2π = Js m p = m H = kg c = m/s m e = kg σ = W/m 2 /K 4 M = kg R = m g = 9.80 m/s 2 M = kg R = m I th = W/m 2 I tp = 1.00 W/m 2 1eV = J 1 T = 10 4 G 1 km = 10 3 m 1 nm = 10 9 m 1 mi = km 1 ms = 10 3 s 1 min = 60 s 1 hr = 3600 s 1day = s 1 yr = days Useful Formulae C (circle) = 2πr D (circle) = 2r A (circle) = πr 2 V (sphere) = 4 3 πr3 A (sphere) = 4πr 2 V (rectangular box) = L W H sin θ = a/c cos θ = b/c tan θ = a/b a 2 = b 2 + c 2 2bc cos A 1 = cos 2 θ + sin 2 θ c 2 = a 2 + b 2 (sin A)/(a) = (sin B)/(b) = (sin C)/(c) v = v + at v 2 = v 2 +2ax x = v t at2 x = 1 2 (v + v )t R = R = R 2 x + R2 y R x = R cos θ R y = R sin θ tan θ = R y x = x + v x t R x v x = v x v y = v y gt v = vx 2 + v2 y y = y + v y t 1 2 gt2 vy 2 = v2 y 2gy θ = tan 1 ( v y v x In the trigonometric equations above, a opposite side, b adjacent side, and c hypotenuse where the angle is θ. Capital letters A, B, and C are the angles opposite the sides a, b, and c, respectively. )

2 Useful Formulae (continued) F = m a Fg = w = m g W =(F cos θ)s = (KE) PE g = mgy KE 1 2 mv2 PE s = 1 2 kx2 KE i +PE i =KE f +PE f p m v ω = ω + αt 1 rev = 2π radians = 360 θ = ω t αt2 ω 2 = ω 2 +2αθ v t = rω a t = rα F c = ma c =(mvt 2)/r = mrω2 a c = v 2 /r F g =(Gm 1 m 2 /r 2 )ˆr, orf g = mg v =2πr/T g = GM/r 2 F c = Mv 2 /r T F = 9 5 T C +32 T C = T F e = k e q 1 q 2 /r12 2 E = F e /q Φ E = EAcos θ = Q tot /ɛ E = k e q/r 2 U = Q 2 /(2C) = 1 2 C( V )2 = 1 2 Q( V ) V = k eq/r I = Q/ t C = κc V = E Ir q = Q ( 1 e t/rc) (charging) τ = RC q = Qe t/rc (discharging) F = qvb sin θ F = BIlsin θ B = µ ni τ = BIAsin θ r = mv/qb B = µ I/(2πr) B l = µ I Φ B = BAcos θ E = N Φ B / t = L I/ t V = E = El = Blv I = E /R =(Blv)/R E = NBAωsin ωt F s = kx PE s = 1 2 kx2 T =1/f =2π m/k T =2π L/g v = (331.3 m/s) T/273 K = fλ v = F/µ, µ = m/l β = 10 log(i/i ) I = P/(4πr 2 ) f = f[(v ± v o )/(v v s )] M = v s /v f n =(n/4l)v, (n =1, 3, 5,...) (one end closed) f n =(n/2l) F/µ (string) f n =(n/2l)v, (n =1, 2, 3,...) (open ends) L =(n/2)λ ω =2πf f n = nf 1 1/λ n = R A Z 2 /n 2 ν = c/λ λ/λ =(λ λ )/λ = v r /c c = E max /B max E = hν = hc/λ F = σt 4 λ max =( mk)/t L =4πσR 2 T 4 1/λ = R A Z 2 [ (1/n 2 ) (1/m 2 ) ] L n = m e v n r n = n h

3 Physics 2020 Name: Sample Exam 4 Summer Part A: Hard Multiple Choice (10 points total, 2 points each, Circle Best Answer). 1. A photon has an energy of ev. What is the wavelength of this photon? a) nm b) 6563 Å c) m d) Å e) 2420 nm 2. What is the orbital angular momentum of an electron in the n = 3 level of hydrogen? a) J s b) J s c) J s d) J s e) J s 3. What is the wavelength of maximum emission for a blackbody of 22,200 K? a) nm b) 8.35 nm c) nm d) 1216 nm e) 130 nm 4. A photon is measured to have a maximum electric-field strength of 6.77 N/C. What is the maximum strength of the magnetic field for this photon? (Help: n=10 9, µ=10 6, M=10 6, G=10 9.) a) 22.6 nt b) 6.77 µt c) 2.00 T d) 44.3 MT e) 2.03 GT 5. What is wavelength of the Balmer limit for ionized helium? (Note that R He = m 1.) a) nm b) nm c) nm d) nm e) nm

4 PHYS-2020: General Physics II Sample Exam 4 Summer 2006 Page 2 Part B: Easy Multiple Choice (10 points total, 1 point each, Circle Best Answer). 6. Particles with symmetric wavefunctions are called a) bosons b) electrons c) quarks d) fermions e) leptons 7. Which of the following is an elementary particle? a) gluon b) weakon c) photon d) muon e) none of these 8. We observe 5 different blackbodies and note the type of light that each emit their maximum amount of flux. Of these, which is the hottest? a) red b) ultraviolet c) green d) infrared e) microwave 9. The state of a particle in classical physics can be given by the particle s a) mass b) charge c) spin d) trajectory e) probability 10. Strong spectral lines that originate out of the ground state are called a) forbidden lines b) semiforbidden lines c) intersystem lines d) resonance lines e) none of these 11. A tube is filled with low pressure gas. If an electric current is passed through this gas, what kind of spectrum will result? a) absorption line b) continuous c) emission line d) reflection e) transparent

5 PHYS-2020: General Physics II Sample Exam 4 Summer 2006 Page Which of the following is not a field particle? a) fermion b) weakon c) gluon d) photon e) graviton 13. Which of the following is the true statement about hadrons? a) Hadrons are all leptons. b) Hadrons are particles that obey the strong force. c) Hadrons are particles that obey the dark side of the force. d) Hadrons obey the weak, electromagnetic, and gravitational forces, but they do not obey the strong force since they do not see gluons. e) None of these are true. 14. Brightness of visible light is to color as loudness of sound is to a) density b) pressure c) flux d) intensity e) pitch 15. The Pauli Exclusion Principle only applies to what type of particles? a) bosons b) photons c) fermions d) gravitons e) mesons

6 PHYS-2020: General Physics II Sample Exam 4 Summer 2006 Page 4 Part C: Problems (20 points total, 10 points each). 16. A 502 nm photon is absorbed by an electron that is in a 3.16 ev state. (a) What would be the energy (in ev) of the new state once it absorbs the photon? (b) While excited, assume that this atom collides with a second stationary electron. After the collision, the bound electron collisionally de-excites to the 0.00 ev ground state and all of the energy of this transition is transferred to the kinetic energy of the stationary electron. How fast would this second electron be traveling after this collision? (Show all work!)

7 PHYS-2020: General Physics II Sample Exam 4 Summer 2006 Page The exhaust of a spaceship shines with a blackbody spectrum at a total flux of W/m 2. (a) What is the temperature of this exhaust? (b) At what wavelength (in nm) does this exhaust emit its maximum flux? (c) If the exhaust of the ship is moving away from us at 9820 km/s, at what wavelength (in nm) would we see its maximum flux? (Show all work!!!)

Physics 2020 Exam 3 Constants and Formulae

Physics 2020 Exam 3 Constants and Formulae Useful Constants k e = 8.99 10 9 N m 2 /C 2 e = 1.60219 10 19 C h = h/2π = 1.05459 10 34 J s h = 6.62620 10 34 J s m p = m H = 1.672 10 27 kg m e = 9.110 10 31