Remigijus (+6)
Sveiki gal galite patikrinti ar siuos uzdavinius issprendziau gerai.
1. Jei lemputės sujungtos lygiagrečiai
Duota Rasti
a) R
U=220V,
P=40W, b) I
n=4
a) U=R*I, P=U*I b) I=P/U
R=U2/P I=4*40W/220V
R=1210Ω I=0,727A
2.
Duota Rasti
m=0,196kg, T
k=200N/m
T=2π
T=0,0139s
3.
Duota Rasti
I=8A, B
F=0,2N,
l=0,2m,
α=30°
B= F/(I*l*sin)
B=0,25T
4.
Duota Rasti
glizerinas n=1,4745, α
oras n~1, α=25°
sin α /sin α = 1,4745
sin α =0,623
α ~38,5°
5.
Duota Rasti
U1=1,2V, I
R1=0,1Ω,
U2=0,9V,
R2=0,3Ω,
R=0,2Ω
I= U/R
I=0,3V /0,6Ω
I=0,5A
6.
Duota Rasti
m=0,89kg, S
R=6,8Ω,
ρ=1,7 *10-18Ωm,
ρtankis=8900 kg/ m-3
R=ρ*(l/A) → l=AR/ρ
S2R/ ρ=m/ρtankis
S= m/R
S=√0,89kg*1,7*10-18Ωm/8900kg m-3 6,8Ω
S=√11,56 10-22m4
S=3,4*10-11m2
7. ir 9. (tie patys uzdaviniai)
Duota Rasti
platinas Wex~5,5eV, vmax
λ=100nm
Wfot = Wex + Wkin
Wfot = h*f = h*c/λ = 6,625 * 10-34 Nms *3 *108 m/s /10-7m = 19,8 10-19Nm
Wex = 5,5 *1,6 *10-19 Nm = 8,8 *10-19 Nm
Wkin = 11 *10-19 Nm =0,5m * v2
v2 = 2* 11 *10-19 Nm / 9,1 *10-31 kg = 2,42 * 1012m2/s2
vmax = 1,55 *106m/s
8.
Duota Rasti
cinkas Wex~4,34 eV, vmax
λ=200nm
Wfot = Wex + Wkin
Wfot = h*f = h*c/λ = 6,625 * 10-34 Nms *3 *108 m/s /2*10-7m
= 9,9 10-19Nm
Wex = 4,34eV = 4,34 *1,6 *10-19 Nm
= 6,94 *10-19 Nm
Wkin = 2,96 *10-19 Nm
=0,5m * v2
v2 = 2* 2,96 *10-19 Nm / 9,1 *10-31 kg
= 0,65 * 1012m2/s2
vmax = 0,8 *106m/s
10.
Duota Rasti
Wkin= 4,5 * 10-20 J, λ
Wex= 76 * 10-20 J
Wfot = Wex + Wkin
=80,5 * 10-20 J
Wfot = h*c/λ → λ = h*c/W
λ = 6,625 * 10-34 Nms *3 *108 m/s /80,5 * 10-20 Nm
=0,25 * 10-6 m
λ = 250nm