Explanation:
Both eras and periods are greater, but an era is more than 1 year
Answer: O
Explanation:
The stars which emit the most blue light are the hotter stars and O type stars are the hottest stars there are.
O stars are larger than every other star and have surface temperatures ranging above 25,000K as well as being extremely bright.
They therefore emit the most blue light and the least red light.
Answer:
8 cm and 9 cm
Explanation:
To estimate the sides of triangle we must understand that any side of a triangle is greater than the differences between any two sides and also less than the sum of the two sides.
In this problem;
One of the sides is 13cm;
According to our theorem, this sides is less than the sum of the other two sides and greater than difference between the two sides.
8 cm and 9 cm is the correct choice;
if the other two sides are 8cm and 9cm;
9cm - 8cm = 1cm
9cm + 8cm = 17cm
13cm is in between them.
Answer:
Explanation:
For a satellite in orbit around a planet, the gravitational force between the planet and the satellite is equal to the centripetal force that keeps the satellite in circular motion.
So, we can write:
where
G is the gravitational constant
M is the mass of the planet
m is the mass of the satellite
r is the orbital radius of the satellite
v is the speed of the satellite
The equation can be rewritten as
Also, we can write the orbital speed as the ratio between the length of the orbit (circumference of the orbit) and orbital period, T:
Substituting into the equation for M,
Here we have:
is the orbital radius
is the orbital period
Substituting, we find the mass of the Saturn:
