Answer:
Most of the stars occupy the region in the diagram along the line called the main sequence. During the stage of their lives in which stars are found on the main sequence line, they are fusing hydrogen in their cores.
Answer:
P= 454.11 N
Explanation:
Since P is the only horizontal force acting on the system, it can be defined as the product of the acceleration by the total mass of the system (both cubes).

The friction force between both cubes (F) is defined as the normal force acting on the smaller cube multiplied by the coefficient of static friction. Since both cubes are subject to the same acceleration:

In order for the small cube to not slide down, the friction force must equal the weight of the small cube:

The smallest magnitude that P can have in order to keep the small cube from sliding downward is 454.11 N
To solve this problem it is necessary to apply the kinematic equations of motion.
By definition we know that the position of a body is given by

Where
Initial position
Initial velocity
a = Acceleration
t= time
And the velocity can be expressed as,

Where,

For our case we have that there is neither initial position nor initial velocity, then

With our values we have
, rearranging to find a,



Therefore the final velocity would be



Therefore the final velocity is 81.14m/s