Answer:
Generally speaking, as the human population grows, our consumption of natural resources increases. More humans consume more freshwater, more land, more clothing, etc. ... For example, natural gas plants have become increasingly more efficient, thus humans are able to obtain more energy out of the same amount of gas.
Rapid population growth is detrimental to achieving economic and social progress and to sustainable management of the natural resource base. But there remains a sizeable gap between the private and social interest in fertility reduction, and this gap needs to be narrowed.
Answer:
T'=70.92°C
Explanation:
Given that
V= 100 L=0.1 m³
P=400 KPa
T=25°C
Work done on the air = 15 KJ
W= -15 KJ
If we assume that air is ideal gas
P V = m R T
R=0.287 KJ/kg.K for air
T= 273 + 25 = 298 K
By putting the values
P V = m R T
400 x 0.1 = m x 0.287 x 298
m=0.46 kg
From first law of thermodynamics
Q= ΔU +W
Insulated piston–cylinder , Q=0
ΔU = m Cv ΔT
ΔU = - W
Cv = 0.71 KJ/kg.k for air
0.46 x 0.71 x (T' -25) = 15
T'=70.92 °C
So the final temperature of air is T'=70.92 °C
0.33 . Equation is Force of friction equals normal force times coefficient of friction, so 6=18u. Divide 6 by 18
Answer:
v = 8 [m/s]
Explanation:
Debemos determinar la velocidad promedio, esta velocidad se define como la relacion entre la distancia recorrida sobre un determinado tiempo.
De esta manera tenemos la siguiente expresion:
v = x/t
donde:
v = velocidad [m/s]
x = distancia = 400 [m]
t = tiempo = 50 [s]
v = 400/50
v = 8 [m/s]
The solution for this problem is:
500 revolution per
minute = 8.33rev /s = 2π*8.33 rad /s = 52.36 rad /s
Angular velocity ω = 2π N
Angular acceleration α= (ω2 - ω1) /t
ω2 = 0
α = - ω1/t = -2π N /t
N = 500 rpm = 8.33 r p s.
α = -2π 8.33 /2.6 =- 20 rad/s^2
