The answer I believe is c
Explanation
During the day when temperatures are higher, the snow melts and water enters the cracks in the rock. When the temperature drops below 0°C the water in the crack freezes and expands by about 9 per cent. This makes the crack larger.
When you add more water to the balloon, it makes it heavier. Therefore it would weigh the balloon down ( increasing mass) and increasing the energy to plummet down. So the answer is B.
الملك - الإتاوات - المحاكم - المجلس الملكي - القانون الروماني
1. Frequency is the number of complete waves that pass a point in a second. 2.Wavelength is the distance between two crests or two troughs. 3.Time period <span> is the time it takes for one complete wave to pass a given point. 4. Amplitude is the height of the wave. Hence option 4 is correct. </span>
Answer:

Explanation:
From the question we are told that
The electric filed is
Generally according to Gauss law
=> 
Given that the electric field is pointing downward , the equation become

Here
is the excess charge on the surface of the earth
is the surface area of the of the earth which is mathematically represented as

Where r is the radius of the earth which has a value 
substituting values


So

Here
s the permitivity of free space with value

substituting values

