Question

Potrzebne na wczoraj :)))

Answer 1

Natężenie:

U = 230V
P = 180W

P = UI => I = P/U

I = 180W/230V = 0,8A - odpowiedź A

Ładunek:

t = 50s
I = 0,8A

I = q/t => q = It

q = 0,8A * 50s = 40C - odpowiedź C

Energia:

P = 180W
t = 50s

P = W/t => W = Pt

W = 50s * 180W = 9000J - odpowiedź D

Energia w ciągu roku:
80g kawy - 50s
160g kawy - t

t = 100s = 0,027h
365*0,027h = 9,855h
P = 180W

W = 180W * 9,855h = 1773,9Wh ~ 2kWh - odpowiedź B

Koszt:

t = 20h
P = 180W

W = 180W*20h = 3600Wh = 3,6kWh

1kWh - 50gr
3,6kWh - x

x = 180gr = 1,80zł - odpowiedź A

Żarówka:
W = 720kJ = 720 000J
t = 10h = 36000s

P = W/t

P = 720 000J/36000s = 20W

Żarówka vol.2:
P = 20W
t = 24h = 86400s

a)
W = Pt
W = 86400s * 20W = 1728000J
1kWh = 1000Wh = 1000J/s*3600s = 3 600 000J

1kWh - 3 600 000J
x - 1728000J

x = 0,48kWh

b)
1kWh - 50gr
0,48kWh - x

x = 24gr

c)
P = 20W
U = 230V

I = P/U

I = 20W/230V = 0,09A

Answer 2

Pozdrawiam, Adam