When an astronaut travels from the earth to the moon, her weight changes, but her mass remains constant. <em>(C ).</em>
Answer:
Explanation:
a ) Between r = 0 and r = r₁
Electric field will be zero . It is so because no charge lies in between r = 0 and r = r₁ .
b ) From r = r₁ to r = r₂
At distance r , charge contained in the sphere of radius r
volume charge density x 4/3 π r³
q = Q x r³ / R³
Applying Gauss's law
4πr² E = q / ε₀
4πr² E = Q x r³ / ε₀R³
E= Q x r / (4πε₀R³)
E ∝ r .
c )
Outside of r = r₂
charge contained in the sphere of radius r = Q
Applying Gauss's law
4πr² E = q / ε₀
4πr² E = Q / ε₀
E = Q / 4πε₀r²
E ∝ 1 / r² .
Answer:
Wolves are a keystone species because they are so important to the ecosystem that their removal causes a catastrophic disequilibrium.
Explanation:
Wolves are the predators available in the environment but they exist in relatively less number while comparing it with another species of animals. Wolves influence their pray which are influenced by plants. Thus, They are so important to the ecosystem that their removal causes a catastrophic disequilibrium.
Answer:
D. The net electrical charge of the Earth.
Explanation:
All the other three choices affect the gravitational force. I remember from middle school.
