Answer:
995 N
Explanation:
Weight of surface, w= 4000N
Gravitational constant, g, is taken as 9.81 hence mass, m of surface is W/g where W is weight of surface
m= 4000/9.81= 407.7472
Using radius of orbit of 6371km
The force of gravity of satellite in its orbit, 
Where
and 

F= 995.01142 then rounded off
F=995N
Answer: work
Explanation:
Often in physics, work is defined as the use of force to move an object. Technically, work is actually a change in energy caused by a force external to the system. The formula for work is W = F⊥d or W = FdcosΘ. Using this formula, we can see that work is just when a force is applied for a certain displacement. In simpler terms, that's just a force used to move an object a certain distance.
The frequency of the radio station is

For radio waves (which are electromagnetic waves), the relationship between frequency f and wavelength

is

where c is the speed of light. Substituting the frequency of the radio station, we find the wavelength:
Answer:
Is the mass number
Explanation:
Every atom is usually identified by using two different numbers:
- Atomic number: generally labelled with Z, corresponds to the number of protons in the nucleus, so Z = p
- Mass number: generally labelled with A, corresponds to the number of protons+neutrons in the nucleus, so A = p + n
To find the number of neutrons in a nucleus, therefore, we can do
n = A - Z