Answer:
a)
, b)
, c) 
Explanation:
a) The change in the gravitational potential energy of the marble-Earth system is:


b) The change in the elastic potential energy of the spring is equal to the change in the gravitational potential energy, then:

c) The spring constant of the gun is:




Answer:
The universal sign for choking is __________.
A.
two balled fists pressing the abdomen
B.
pointing at an open mouth
C.
two hands grasping the neck
D.
pretending to cough
Explanation:
Water vapor clouds that are breaking out of Europe’s surface, water is the basis of life so this would support the idea that there is life
Answer:True
Explanation:
Albedo is a unit-less, non-dimensional quantity that shows how well a surface reflects solar energy. The value of albedo can vary from 0 to 1, 0 being the black and 1 refers to a white surface. Zero means Surface is a perfect absorber i.e. it absorbs all the incoming rays incidents on it. Albedo 1 means the surface is a perfect reflector.
Albedo usually applies for visible light, even though it may involve some of the infrared regions of the electromagnetic spectrum. The average albedo associated with earth surface is 30%
The correct answer is the third one: move toward the ground state. Remember please that Elements produce their spectrum when their electrons move toward the ground state. Hope this is very useful