The gravitational force between two objects is given by:

where
G is the gravitational constant
m1 and m2 are the masses of the two objects
r is the separation between the two objects
The distance of the telescope from the Earth's center is

, the gravitational force is

and the mass of the Earth is

, therefore we can rearrange the previous equation to find m2, the mass of the telescope:
I think you can just sub the values in? unless the qn is asking for smth else?
Answer:
Temperature at the exit = 
Explanation:
For the steady energy flow through a control volume, the power output is given as

Inlet area of the turbine = 
To find the mass flow rate, we can apply the ideal gas laws to estimate the specific volume, from there we can get the mass flow rate.
Assuming Argon behaves as an Ideal gas, we have the specific volume 
as


for Ideal gasses, the enthalpy change can be calculated using the formula

hence we have


<em>Note: to convert the Kinetic energy term to kilojoules, it was multiplied by 1000</em>
evaluating the above equation, we have 
Hence, the temperature at the exit = 
Answer: because they have equal numbers of protons
Explanation: Atoms are electrically neutral because they have equal numbers of protons (positively charged) and electrons (negatively charged). If an atom gains or loses one or more electrons, it becomes an ion