Question

1.Podaj, czas w jakim kopalniany transporter o mocy 36kW przemieści 14400kg węgla na wysokość 200m.

Answer 1

P = 36 kW = 36000 W = 36000 J/s
m = 14400 kg
h = s = 200 m
g = 10 m/s^2
t = ?

P = W/t ; ale W = F*s
P = F*s /t ; ale F = m*g

P = m*g*h /t
P*t = m*g*h
t = m*g*h/P

t = 14400 kg * 10 m/s^2 *200 m/36000 W
t = 28800000 kg*m^2/s^2 / 36000 J/s
t = 800 s= 800 s/60 = 13,3 min

[J]= [ kg*m^2/s^2]