<span>The statement, Sunlight is a
form of electromagnetic energy, is true. The answer is letter A. Electromagnetic
energy is a form of radiant energy that released by electromagnetic radiation. One
example of an electromagnetic radiation is the visible light. And visible light
can be radio waves, infrared light and X - rays. The rays of the sun are a form
of visible light. It has an electromagnetic radiation of UV (ultra violet)
rays. That is why the radiation at day is greater than at day due to sun’s
rays. </span>
The heat and energy of coal burning is more easier and more efficient to turn into electricity than any method using renewable resources.
Explanation:
Work cannot be increased by using a machine of some kind.
The energy transfer in terms of work has the equation:
W = mΔ(PV)
To be consistent with units, let's convert them first as follows:
P₁ = 80 lbf/in² * (1 ft/12 in)² = 5/9 lbf/ft²
P₂ = 20 lbf/in² * (1 ft/12 in)² = 5/36 lbf/ft²
V₁ = 4 ft³/lbm
V₂ = 11 ft³/lbm
W = m(P₂V₂ - P₁V₁)
W = (14.5 lbm)[(5/36 lbf/ft²)(4 ft³/lbm) - (5/9 lbf/ft²)(11 lbm/ft³)]
W = -80.556 ft·lbf
In 1 Btu, there is 779 ft·lbf. Thus, work in Btu is:
W = -80.556 ft·lbf(1 Btu/779 ft·lbf)
<em>W = -0.1034 BTU</em>
Given parameters:
Displacement = 8km
Velocity = 3.8km/h
Unknown:
time = ?
Solution:
Velocity is displacement divided by time.
Velocity = 
Displacement = velocity x time
Input the parameters:
8 = 3.8 x time
Time = 
= 2.1s
The time taken is 2.1s
