Infrared waves have lower frequency that UV rays.
Explanation:
a) The height of the ball h with respect to the reference line is
so its initial gravitational potential energy 
is
b) To find the speed of the ball at the reference point, let's use the conservation law of energy:
We know that the initial kinetic energy 
as well as its final gravitational potential energy 
are zero so we can write the conservation law as
Note that the mass gets cancelled out and then we solve for the velocity v as
Answer:
2.5 * 10^-3
Explanation:
<u>solution:</u>
The simplest solution is obtained if we assume that this is a two-dimensional steady flow, since in that case there are no dependencies upon the z coordinate or time t. Also, we will assume that there are no additional arbitrary purely x dependent functions f (x) in the velocity component v. The continuity equation for a two-dimensional in compressible flow states:
<em>δu/δx+δv/δy=0</em>
so that:
<em>δv/δy= -δu/δx</em>
Now, since u = Uy/δ, where δ = cx^1/2, we have that:
<em>u=U*y/cx^1/2</em>
and we obtain:
<em>δv/δy=U*y/2cx^3/2</em>
The last equation can be integrated to obtain (while also using the condition of simplest solution - no z or t dependence, and no additional arbitrary functions of x):
v=∫δv/δy(dy)=U*y/4cx^1/2
=y/x*(U*y/4cx^1/2)
=u*y/4x
which is exactly what we needed to demonstrate.
Also, using u = U*y/δ in the last equation we can obtain:
v/U=u*y/4*U*x
=y^2/4*δ*x
which obviously attains its maximum value for the which is y = δ (boundary-layer edge). So, finally:
(v/U)_max=δ^2/4δx
=δ/4x
=2.5 * 10^-3
Answer:
Total energy is 170 kJ
Explanation:
Given data:
latent heat of fusion of alcohol is 25 kcal/kg
melting point of alcohol is -114 degree c
specific heat us 0.60 k cal/kg degree c
energy need for 2 kg solid alcohol is
for Melting:
Energy Q is calculated as
Energy, Q = 25 \times 2.0 kg = 50 kJ
Energy required for Heating liquid:
Energy, ΔH = 2.0 kg \times 0.60 \times (100°C) = 120 kJ
Total energy = (50 kJ + 120 kJ) = 170 kJ
With the given values of 
, we have
Try dealing with the powers of 10 first: On the right, we have
Meanwhile, the other values on the right reduce to
Then taking units into account, we end up with the equation
Now we solve for 
:
or, if taking significant digits into account,
