Answer:
Well, the options are not given in the questions. But the correct option is:
"Gamma rays do not completely penetrate earth atmosphere."
Explanation:
Most of the gamma rays coming from the stars and sun can not penetrate the earth's atmosphere because atmosphere is as thick to the gamma rays as a 12 foot thick plate of aluminium. They rather absorb in the atmosphere and knock out electrons by reacting with the atoms and produce ions and electrons. These secondary ions and electrons then came to earth during rain fall. Due to this reason gamma ray telescope was not get funded for the study of black holes.
The pressure is 
.
Answer: Option A
<u>Explanation:</u>
Pressure defines the force acting per single area. So depending upon the amount of force acting over a given area in the perpendicular direction of the object, the pressure acting on that area will vary.
So the pressure is directly proportionate to the applied force on a particular region and inversely proportionate into the areas of the region. Hence, the unit of pressure is considered as 
or Pascal. Pressure can also be termed as the number of air molecules present in a specified closed region. Thus, for the present condition
Thus, by appling the given values in the above equation, we get,
=
So the pressure is .
The height of the plane delivering a food package to people stranded on an island is 722.2 m.
<h3>
Time of motion of the food package</h3>
The time taken for the food package to hit the ground level is calculated as follows;
X = vt
where;
- X is horizontal distance traveled by the food package
- v is horizontal distance
- t is time of motion
t = X/v
t = 789/65
t = 12.14 seconds
<h3>Height of the plane</h3>
h = ¹/₂gt²
where;
- h is height of fall of the food package which is height of the plane
- t is time of motion of food package
- g is acceleration due to gravity
h = (0.5)(9.8)(12.14²)
h = 722.2 m
Thus, the height of the plane delivering a food package to people stranded on an island is 722.2 m.
Learn more about height here: brainly.com/question/1739912
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To solve the exercise it is necessary to use the reciprocal Lorenz factor of the special theory of relativity with the pulse rate.
Where,
Pulse rate measured by earth observed
Reciprocal Lorenz Factor
Here v is the velocity and c the light speed.
PART A) For the given values we can replace it at the previous equation,
PART B ) If the speed of vehicle is 0.94c:
