Answer:
the unit of work is derived unit because joule is defined the work done by the force aftab 1 newton causing the displacement of one metre something newton metre(n-m) is also used to measuring work.
So lunar eclips earth between sun and moon
Solar eclips moon between sun and earth.
About the 3th.. im not sure, it depends on if you meen a total solar eclips or not... i think total is more rare then a lunar eclipse..
The average dissipated power in a resistor in a ac circuit is:

where R is the resistance, and

is the root mean square current, defined as

where

is the peak value of the current. Substituting the second formula into the first one, we find

and if we re-arrange this formula and use the data of the problem, we can find the value of the peak current I0:
Complete Question
A wave is described by y(x,t) = 0.1 sin(3x + 10t), where x is in meters, y is in centimetres and t is in seconds. The angular wave frequency is
Answer:
The value is 
Explanation:
From the question we are told that
The equation describing the wave is y(x,t) = 0.1 sin(3x + 10t)
Generally the sinusoidal equation representing the motion of a wave is mathematically represented as

Where w is the angular frequency
Now comparing this equation with that given we see that

The refractive index for glycerine is

, while for air it is

.
When the light travels from a medium with greater refractive index to a medium with lower refractive index, there is a critical angle over which there is no refraction, but all the light is reflected. This critical angle is given by:

where n1 and n2 are the refractive indices of the two mediums. If we susbtitute the refractive index of glycerine and air in the formula, we find the critical angle for this case: