Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space. ... This proved that radio waves were a form of light!
Answer:
During this time period, the axis of the earth is tilted by 23.5°. As our earth revolves around the sun and completes its one rotation in 365 days. During this rotation in the month of June the Northern Hemisphere “leans into” the sun and experiences more radiations coming from the sun.
That is why it is more illuminated and hot. While in December Northern Hemisphere leans away and the Southern Hemisphere leans into the Sun.
Whereas in September and march the earth the hemispheres are equally favored by sunshine and the earth neither leans into the sun nor away from the sun.
Answer:
The magnitude of the heat transfer rate from the compressor is 87.05 kW
Explanation:
Initial pressure of refrigerant = 4 bar
Final pressure of refrigerant = 12 bar
From steam table,
Internal energy at 4 bar (U1) = 2554 kJ/kg
Internal energy at 12 bar (U2) = 2588 kJ/kg
Change in internal energy (∆U) = U2 - U1 = 2588 - 2554 = 34 kJ
Work input (W) = 120 kJ/kg
Quantity of heat transfer (Q) = ∆U + W = 34 + 120 = 154 kJ/kg
Volumetric flow rate of refrigerant = 8 m^3/min = 8/60 = 0.133 m^3/s
Density of refrigerant = 4.25 kg/m^3
Mass flow rate = density × volumetric flow rate = 4.25 kg/m^3 × 0.133 m^3/s = 0.56525 kg/s
Q = 154 kJ/kg × 0.56525 kg/s = 87.05 kJ/s = 87.05 kW
(a) 
The average acceleration of the ship is given by
where
v is the final velocity
u is the initial velocity
t is the time elapsed
Here we have:
is the initial velocity
v = 0 is the final velocity
is the time elapsed
Substituting, we find
(b) 4.72 m/s
Assuming the acceleration is uniform, the average velocity of the ship is given by:
where
v is the final velocity
u is the initial velocity
Here we have:
v = 0
u = 9.44 m/s
So the average velocity of the ship is
Answer:
Total pressure =1.01*10^5 Pa
Explanation:
given data:
atmospheric pressure = 1.013 *10^5 Pa\
height of water column = 60 cm
Total pressure will be sum of atmospheric pressure and pressure due to water column
P = Atmospheric pressure + pressure due to water column
pressure due to water =
\rho of water = 1420 kg/m^{3}
height of water column = 60 cm =0.60 m
Total pressure = 109649.6 Pa = 1.10*10^5 Pa
Total pressure =1.01*10^5 Pa
