Trust me, i'm a k12 student and its motor
Gravity obeys the inverse square law. At 6400 km above the center of the Earth (Earth's surface) you weigh x. Twice that reduces your weight to 1/4th. Four times that height reduces your weight to 1/16th. 4 times 6400 km is 25,600 km. But that is above the center of the earth, and the question requests the height above the surface, so we deduct 6400 km to arrive at our final answer: 19,200 km.
Incidentally, it doesn't exactly work the opposite way. At the center of the Earth the mass would be equally distributed around you, and you would therefore be weightless.
Using the addition of forces using right angled triangles. The resultant force sqaured. = 112.8 sqaured + 52.6 squared. So resultant force sqaured is 15490.6. So the resultant force is the sqaure root of this which is 124N to 3 significant figures
The cell theory states that:
1) All living organisms are composed of one or more cells.
2) The cell is the basic unit of structure and organization in organisms.
3) Cells arise from pre-existing cells.
Your statement is not present, so the answer would be no.
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The heat capacity is given by the expression:
When the 
is measured in the calorimeter, we obtain a value, and since we know the mass of the material and we control the change in 
, we can then determine the specific heat "C" by simply remplazing in the expression.
