Answer:
D Reflection
Explanation:
It reflects the light from the sun. Then when the earth gets in the way, it casts a shadow causing crescent moons.
Answer:
They find problems and solutions by working together
Explanation:
Answer:
Assumption:
1. The kinetic and potential energy changes are negligible
2. The cylinder is well insulated and thus heat transfer is negligible.
3. The thermal energy stored in the cylinder itself is negligible.
4. The process is stated to be reversible
Analysis:
a. This is reversible adiabatic(i.e isentropic) process and thus 
From the refrigerant table A11-A13

sat vapor
m=

b.) We take the content of the cylinder as the sysytem.
This is a closed system since no mass leaves or enters.
Hence, the energy balance for adiabatic closed system can be expressed as:
ΔE
ΔU
)
workdone during the isentropic process
=5.8491(246.82-219.9)
=5.8491(26.91)
=157.3993
=157.4kJ
Answer:
(a) 11.437 psia
(b) 13.963 psia
Explanation:
The pressure exerted by a fluid can be estimated by multiplying the density of the fluid, acceleration due to gravity and the depth of the fluid. To determine the fluid density, we have:
fluid density = specific gravity * density of water = 1.25 * 62.4 lbm/ft^3 = 78 lbm/ft^3
height = 28 in * (1 ft/12 in) = 2.33 ft
acceleration due to gravity = 32.174 ft/s^2
The change in pressure = fluid density*acceleration due to gravity*height = 78*32.174*(28/12) = 5855.668 lbm*ft/(s^2 * ft^2) = 5855.668 lbf/ft^2
The we convert from lbf/ft^2 to psi:
(5855.668/32.174)*0.00694 psi = 1.263 psi
(a) pressure = atmospheric pressure - change in pressure = 12.7 - 1.263 = 11.437 psia
(b) pressure = atmospheric pressure + change in pressure = 12.7 + 1.263 = 13.963 psia