Yes, the answer is in fact C. All of the above.
Variable stars are stars that change in brightness. The change could be due to the physical change in the star or it could also be caused when another star crosses another, or in other words eclipse.
Answer:
10
Explanation:
(r) = <10 cos 6t, 10 Sin 6t>
The distance traveled by the object is the magnitude of vector r.
The magnitude of vector r is given by


r = 10
Answer: 
Explanation:
According to Newton's 2nd Law of motion the force
is proportional to the mass
and acceleration
:
(1)
On the other hand, the equation for the Centripetal force is:
(2)
Where:
is the velocity
is the radius of the circular motion
Making (1) and (2) equal:
(3)
Hence:
This is the expression for the centripetal acceleration
It should be noted, this acceleration is directed toward the center of the circumference of the circular motion (that's why it's called centripetal acceleration).