Abstract. Abstract is defined as an idea or plan but no actions are done
to pursue the idea. When setting goals, one must be certain and it should be attainable in order
to achieve the goal being set. Goals that are abstract
are often poorly written and uncertain
:)
Answer:
Yes, it is reckless. This is because it is the responsibility of the pilot to make sure that the direction of the propeller blast is away from people or other aircraft and in a safe direction.
Explanation:
Yes, it is reckless to let the propeller blast face people and other aircraft. This is because it is the responsibility of the pilot to make sure that the direction of the propeller blast is away from people or other aircraft and in a safe direction. People and other aircraft can be injured by the debris and the rocks that are scattered by the engine of the aircraft.
Answer: 
Explanation:
If we make an analysis of the net force
of the rock that was thrown upwards, we will have the following:
(1)
Where:
is the force with which the rock was thrown
is the weight of the rock
Being the weight the relation between the mass
of the rock and the acceleration due gravity
:
(2)
(3)
Substituting (3) in (1):
(4)
(5) This is the net Force on the rock
On the other hand, we know this force is equal to the multiplication of the mass with the acceleration, according to Newton's 2nd Law:
(6)
Finding the acceleration
:
(7)
(8)
Finally:
The refractive index for glycerine is

, while for air it is

.
When the light travels from a medium with greater refractive index to a medium with lower refractive index, there is a critical angle over which there is no refraction, but all the light is reflected. This critical angle is given by:

where n1 and n2 are the refractive indices of the two mediums. If we susbtitute the refractive index of glycerine and air in the formula, we find the critical angle for this case:
Answer:
gdgdrhhdhhsbsnjsjdgjdjdjsbdubjdbfn
Explanation:
nnndhdhjdjddjrjjdkdnfidjdbdjbdksjd