Answer:
option D
Explanation:
Sunspots are the spot that appears on the sun, this spot appears darker than the surrounding surface of the sun.
Sun magnetic field goes through a cycle and this cycle is called the Sunspot cycle. Every 11 years the magnetic field of the sun completely flips. This sunspot cycle affects activity on the surface of the sun.
Sunspot cycle is the pattern of solar activity where an average number of sunspot gradually increase and decrease.
Hence, the correct answer is option D
The preamble rock is filled with air spaces
I think they decrease echo and reduce noise, they do this by either absorbing vibrations or by scattering the sound so that echoes arrive at different times rather than reverberating as a standing wave. An echo is a reflection of a sound that arrives at the listener with a delay after the direct sound. The delay is usually proportional to the distance of the reflecting surface from the source and the listener.
Answer:
Explanation:
speed is define as rate of change of distance or displacement
v=s/t
s=8 m
t=4s
v=8/4
v=2 m/s
Answer:


Explanation:
A denotes Alex
M denotes Mary
r = Distance from center
Mary and Alex will have the equal displacements in equal interval of time as they are in uniform circular motion. So,

Tangential speed speed is given by

The tangential speed of Mary is 