Answer:
P= 5.5 bar
Explanation:
Given that
L= 4000 m
d= 0.2 m
Friction factor(F) = 0.01
speed V= 2 m/s
Head = 5 m
Head loss due to friction



So the total head(H) = 5 + 40.77 + 10.3 =56.07
Where 10.3 m is the atmospheric head.
We know that
P=ρ g H
So total Pressure
P= 1000 x 9.81 x 56.07 Pa

P= 5.5 bar
Answer:
The surface temperature increases when two bodies are rubbed against each other due to friction.
Explanation:
No object has a perfectly even surface. So, when two bodies with uneven surfaces are rubbed against each other, they experience friction.
Friction is a resistance experienced by the two bodies when they are moved against each other.
The friction between the two surfaces, converts the kinetic energy of the movement to the thermal energy.
Thus, resulting in rise in the surface temperature of the two bodies.
Therefore, when two bodies are rubbed against each other, the surface temperature increases due to friction.
Answer:
a mass of water required is mw= 1273.26 gr = 1.27376 Kg
Explanation:
Assuming that the steam also gives out latent heat, the heat provided should be same for cooling the hot water than cooling the steam and condense it completely:
Q = mw * cw * ΔTw = ms * cs * ΔTw + ms * L
where m = mass , c= specific heat , ΔT=temperature change, L = latent heat of condensation
therefore
mw = ( ms * cs * ΔTw + ms * L )/ (cw * ΔTw )
replacing values
mw = [182g * 2.078 J/g°C*(118°C-100°C) + 118 g * 2260 J/g ] /[4.187 J/g°C * (90.7°C-39.4°C)] = 1273.26 gr = 1.27376 Kg