Answer:
  Mg- 27   means isotope with 12 protons and 15 neutrons.
Also 27 is mass number which express sum of protons and neutrons.
In nucleus one neutrn decays to electron and proton. Mass number remain same but Al-27 nucleus contain 13 protons and 14 neutrons. Electron is ejected out from nucleus.
 
        
             
        
        
        
Answer:

Explanation:
The horizontal distance covered by the ball in the falling is only determined by its horizontal motion - in fact, it is given by

where
 is the horizontal velocity
 is the horizontal velocity
t is the time of flight
The time of flight, instead, is only determined by the vertical motion of the ball: however, in this problem the vertical velocity is not changed (it is zero in both cases), so the time of flight remains the same.
In the first situation, the horizontal distance covered is

in the second case, the horizontal velocity is increased to

And so the new distance travelled will be

So, the distance increases linearly with the horizontal velocity.
 
        
             
        
        
        
Answer:
1250 J
Explanation:
Work is said to be done when a force causes an object to move over a distance. The amount of work done (W) is calculated by multiplying the force by the distance traveled.
That is;
W = F × d
Where;
W = work done (J or N/m)
F = force (N)
d = distance (m)
Based on the information provided in this question, F = 5000N, d = 0.25m
Hence;
W = F × d
W = 5000 × 0.25
W = 1250J
Therefore, 1250Joules of work is done by the jack.
 
        
             
        
        
        
Answer: True 
Explanation: Because of the way this water cycle has always circulated our planet, there is indeed a chance that the water in your glass is the same water that thirsty dinosaurs were drinking about 65 million years ago
 
        
                    
             
        
        
        
C. 5
a neutral atom has no electrical charge. protons are positive and electrons are negative, they need to be the same to make it a neutral atom.