If a person want to move a <span>heavy box across the room, he must apply a force that is greater than starting frictional force acted on the heavy box in order to get the box in motion. the frictional force is equal to coefficient of friction times the normal force, and normal force is approximately the weight of the object. so the force that must be applied must be greater than the wieght of the object.</span>
Answer:
D: Conducts electrcity poorly
Explanation:
Most conductors are metals, and non- metals are insulators, therefore they dont conduct electricity
Answer:
The number is 
Explanation:
From the question we are told that
The wavelength is 
The length of the glass plates is 
The distance between the plates (radius of wire ) = 
Generally the condition for constructive interference in a film is mathematically represented as
![2 * t = [m + \frac{1}{2} ]\lambda](https://tex.z-dn.net/?f=2%20%2A%20%20t%20%20%3D%20%5Bm%20%2B%20%20%5Cfrac%7B1%7D%7B2%7D%20%20%5D%5Clambda)
Where t is the thickness of the separation between the glass i.e
t = 0 at the edge where the glasses are touching each other and
t = 2d at the edge where the glasses are separated by the wire
m is the order of the fringe it starts from 0, 1 , 2 ...
So
![2 * 2 * d = [m + \frac{1}{2} ] 520 *10^{-9}](https://tex.z-dn.net/?f=2%20%2A%20%202%20%2A%20d%20%20%20%3D%20%5Bm%20%2B%20%20%5Cfrac%7B1%7D%7B2%7D%20%20%5D%20520%20%2A10%5E%7B-9%7D)
=> ![2 * 2 * (2.8 *10^{-5}) = [m + \frac{1}{2} ] 520 *10^{-9}](https://tex.z-dn.net/?f=2%20%2A%20%202%20%2A%20%20%20%282.8%20%2A10%5E%7B-5%7D%29%20%3D%20%5Bm%20%2B%20%20%5Cfrac%7B1%7D%7B2%7D%20%20%5D%20520%20%2A10%5E%7B-9%7D)
=>

given that we start counting m from zero
it means that the number of bright fringes that would appear is

=> 
=> 
Answer:
Less than
Explanation:
Speed of sound increases with density of the medium. Since wood is less dense than water, the speed of sound is lower in wood.