Answer:
Intensity of beam 18 feet below the surface is about 0.02%
Explanation:
Using Lambert's law
Let dI / dt = kI, where k is a proportionality constant, I is intensity of incident light and t is thickness of the medium
then dI / I = kdt
taking log,
ln(I) = kt + ln C
I = Ce^kt
t=0=>I=I(0)=>C=I(0)
I = I(0)e^kt
t=3 & I=0.25I(0)=>0.25=e^3k
k = ln(0.25)/3
k = -1.386/3
k = -0.4621
I = I(0)e^(-0.4621t)
I(18) = I(0)e^(-0.4621*18)
I(18) = 0.00024413I(0)
Intensity of beam 18 feet below the surface is about 0.2%
Answer:
<h2>
The potential difference increases </h2>
Explanation:
from the relation 
where E= electric field (force per coulomb)
V= voltage
d= distance
Hence the voltage is going to be V= E×d.
Therefore this means that increasing the distance increases the voltage.
Answer:
The distance of separation is 
Explanation:
The mass of the each ball is 
The negative charge on each ball is 
Now we are told that the lower ball is restrained from moving this implies that the net force acting on it is zero
Hence the gravitational force acting on the lower ball is equivalent to the electrostatic force i.e

=> 
here k the the coulomb's constant with a value 
So
![0.01 * 9.8 = \frac{ 9*10^9 *[1*10^{-6} * 1*10^{-6}]}{d}](https://tex.z-dn.net/?f=0.01%20%2A%209.8%20%20%3D%20%20%5Cfrac%7B%209%2A10%5E9%20%2A%5B1%2A10%5E%7B-6%7D%20%2A%201%2A10%5E%7B-6%7D%5D%7D%7Bd%7D)

Answer:
Net electric field, 
Explanation:
Given that,
Charge 1, 
Charge 2, 
distance, d = 3.2 cm = 0.032 m
Electric field due to charge 1 is given by :



Electric field due to charge 2 is given by :



The point charges have opposite charge. So, the net electric field is given by the sum of electric field due to both charges as :



So, the electric field strength at the midpoint between the two charges is 91406.24 N/C. Hence, this is the required solution.
To solve this problem it is necessary to use the given proportions of power and energy, as well as the energy conversion factor in Jules to Calories.
The power is defined as the amount of energy lost per second and whose unit is Watt. Therefore the energy loss rate given in seconds was


The rate of energy loss per day would then be,


That is to say that Energy in Jules per lost day is 5356800J
By definition we know that 
In this way the energy in Cal is,


The number of kilocalories (food calories) must be 1279.694 KCal