Sunday, July 20, marked 45 years since the United States put the first two astronauts safely on the moon. The cost for the Mercury, Gemini and Apollo programs was more than $25 billion at the time more like $110 billion in today’s world. The ensuing U.S. space efforts have cost an additional $196 billion for the shuttle and $50 billion for the space station. NASA’s total inflation-adjusted costs have been more than $900 billion since its creation in 1958 through 2014 (more than $16 billion per year). Looking back, have we gotten our money’s worth from the investment?
IamSugarBee
Answer:
Explanation:
- We have to make a hollow sphere of inner radius
and outer radius 
.
Then the mass of the material required to make such a sphere would be calculated as:
Total volume of the spherical shell:
And the volume of the hollow space in the sphere:
Therefore the net volume of material required to make the sphere:
- Now let the density of the of the material be
.
<u>Then the mass of the material used is:</u>
Answer:
dT(t)/dt = k[T5 - T(t)]
Explanation:
Since T(t) represents the temperature of the object and T5 represents the temperature of the surroundings, according to Newton's law of cooling, the rate at which an object's temperature changes is directly proportional to the difference in temperature between the object and the surrounding medium, that is dT(t)/dt ∝ T5 - T(t)
Introducing the constant of proportionality
dT(t)/dt = k[T5 - T(t)]
which is the desired differential equation
Answer:
The answer is A, B, C and D
Explanation:
(is that how it works?)
