Answer:
Explanation:
We know that , for an object to remain in circular motion , a force towards centre is required which is called centripetal force. In the circular motion of
satellites around planet , this force is provided by the gravitational attraction between satellite and planet.
If M be the mass of planet and m be the mass of satellite, G be gravitational constant and R be the distance between planet and satellite or R be the radius of orbit
Gravitational force = G Mm / R²
If v be the velocity with which satellite is orbiting
centripetal force
= m v² /R
Centripetal force = gravitational attraction
m v² /R = G Mm / R²
v = 
Time period = time the satellite takes to make one rotation
= distance / orbital velocity
= 2πR/ v
= 
T = 
Answer:
The total voltage of the circuit is 18 volts.
Explanation:
We have, three identical resistors of resistance 3 ohms are connected in series in a circuit.
For a series combination, the equivalent resistance is given by the sum of individual resistances i.e.

Let V is the voltage of the battery if the current in the circuit is 2 A. So,


So, the total voltage of the circuit is 18 volts.
<span>Let's put it this way. Say you have a killer-whale and a penguin. Killer-whales are major predators to penguins. Now, say the killer-whale population increases. The penguins would be eaten more by the killer-whales, then causing a population decrease for the penguins. If the population decreases, they're won't be enough penguins, and they most likely will become extinct, as well as causing a population decrease for the killer-whales as well. Whereas, vis versa, they're were a killer-whale population decrease. The penguins would be less hunted, therefore, creating a population increase for the penguins.</span>
Answer:
Explanation:
All the rest of the information is extraneous. The only 2 things you have to know are
d = 20 km
t = 8 minutes = 8/60 hours = 0.13333333
So the speed is s = d/t
s = 20/0.1333333 = 150 km/hour
Note: you have not specified what units the speed is. I suppose you could answer 20/8 = 2.5 km/min
Answer:
Hans Christian Oersted began a new scientific epoch when he discovered that electricity and magnetism are linked. He showed by experiment that an electric current flowing through a wire could move a nearby magnet. The discovery of electromagnetism set the stage for the eventual development of our modern technology-based world.
Explanation: