To find the ratio of planetary speeds Va/Vb we need the orbital velocity formula:
V=√({G*M}/R), where G is the gravitational constant, M is the mass of the distant star and R is the distance of the planet from the star it is orbiting.
So Va/Vb=[√( {G*M}/Ra) ] / [√( {G*M}/Rb) ], in our case Ra = 7.8*Rb
Va/Vb=[ √( {G*M}/{7.8*Rb} ) ] / [√( {G*M}/Rb )], we put everything under one square root by the rule: (√a) / (√b) = √(a/b)
Va/Vb=√ [ { (G*M)/(7.8*Rb) } / { (G*M)/(Rb) } ], when we cancel out G, M and Rb we get:
Va/Vb=√(1/7.8)/(1/1)=√(1/7.8)=0.358 so the ratio of Va/Vb = 0.358.
Answer:
Explanation:
Given
side of square shape 
Electric flux 
Permittivity of free space 
Flux is given by
where E=electric field strength
A=area
=Angle between Electric field and area vector
and Electric field by a uniformly charged sheet is given by
where 
=charge density
Answer: The specific heat capacity is very low.
Explanation:
The specific heat capacity of a body is defined as the heat energy required by a body to cause a unit change in its temperature. The value is over low that is why it is easier for the desert sand to easily get very hot during the day. Conversely, it is very easy for the desert sand to lose it's heat a cool breeze pass over it in the night making it very cold in the night. This value also defines how long the desert sand can retain heat. Therefore, the desert sand has a low specific heat capacity.
