Answer:
A 3 feet radius snowball will melt in 54 hours.
Explanation:
As we can assume that the rate of snowball takes to melt is proportional to the surface area, then the rate for a 3 feet radius will be:
T= A(3 ft)/A(1 ft) * 6 hr
A is the area of the snowballs. For a spherical geometry is computing as:
A=4.pi.R^2
Then dividing the areas:
A(3 feet)/A(1 foot) = (4 pi (3 ft)^2)/(4 pi (1 ft)^2) = (36pi ft^2)/(4pi ft^2)= 9
Finally, the rate for the 3 feet radius snowball is:
T= 9 * 6 hr = 54 hr
Streamline
Effect
Drag
Parachutes
Surface area
Friction
Air
Water
To solve this problem it is necessary to apply the concepts related to the law of Malus which describe the intensity of light passing through a polarizer. Mathematically this law can be described as:

Where,
Indicates the intensity of the light before passing through the polarizer
I = Resulting intensity
= Indicates the angle between the axis of the analyzer and the polarization axis of the incident light
From the law of Malus when the light passes at a vertical angle through the first polarizer its intensity is reduced by half therefore

In the case of the second polarizer the angle is directly 60 degrees therefore



In the case of the third polarizer, the angle is reflected on the perpendicular, therefore, its angle of index would be

Then,



Then the intensity at the end of the polarized lenses will be equivalent to 0.09375 of the initial intensity.
Answer:
(a) 
(b) 
Explanation:
Parameter given:
Electric field, E = 
(a) Electric force is given (in terms of electric field) as a product of electric charge and electric field.
Mathematically:

Electric charge, q, of an electron = 

(b) This electrostatic force causes the electron to accelerate with an equivalent force:
F = -ma
where m = mass of an electron
a = acceleration of electron
(Note: the force is negative cos the direction of the force is opposite the direction of the electron)
Therefore:

Mass, m, of an electron = 
=> 
The acceleration of the electron is 
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