The spring constant is computed by:
F = kx
Where: F is the force applied in newtons (N)
k is the spring constant measured in newtons per meter (N/m); and
x is the distance the spring is stretched (m)
and
F = mg
Where: F is the force pulling objects in the direction of the Earth.
m is the mass of the object.
g is the acceleration due to gravity;
So plugging our values in the formula:
F = mg
= (1.8) (9.81) = 17.658N
k =
F/x = 17.658 /0.09 = 196.2 N/meter
Answer:
Distance in mm will be 0.3718 mm
Explanation:
We have given charge surface charge density 
We know that electric field due to surface charge density is given by

We have given potential difference V = 105 volt
We know that potential difference is given by 
So 

Answer:
The answer here would be light bulb.
Explanation:
An Illuminated object is simply something that reflects light. And everything in the list is illuminated except the light bulb. Humans reflect light in the same way as desks and sidewalks. If we didn't we wouldn't technically be able to see other humans unless they were luminous. This brings me to the nest point. A light bulb is a luminous object because <em>it creates light on its own. </em>
A good example would be this:
The Sun is a luminous object
The Moon is a illuminated object
I hope this helped and didn't confuse you more, I kind of went all over the place with the explanation. Either way, if you need more help feel free to let me know! :)
-Matt
An example of a mechanical wave is a sound wave