Answer:
Local action is removed by amalgamating zinc rod.
Explanation:
This prevents chemical reaction to occur because impurities in the zinc cannot get into contact with an electrolyte.
 
        
             
        
        
        
Answer:
h = 22.35 m
Explanation:
given,
initial speed of the rock,u = 0 m/s
length of the window,l = 2.7 m
time taken to cross the window,t = 0.129 s
Speed of the rock when it crosses the window
 
 
   v = 20.93 m/s
height of the building above the window
using equation of motion
v² = u² + 2 g h 
20.93² = 0² + 2 x 9.8 x h
h = 22.35 m
Hence, the height of the building above the top of window is equal to h = 22.35 m
 
        
             
        
        
        
<span>Δ</span>E = q + w
q = heat (quantity of)
q and w can be positive or negative depending on if work/heat is being absorbed/done on the system or released/done by the system
        
                    
             
        
        
        
Risk of not being able to reduce their weight
        
             
        
        
        
Because the Earth's axis is not "straight up and down" as we move 
around the sun.  
So when we're on one side of the sun, the top pole leans slightly toward 
the sun.  During that time the sun shines more directly on the top half 
of the Earth, and less directly on the bottom half.  The people on the 
top half see the sun higher in the sky, and their weather is warmer, 
while the people on the bottom half see the sun lower in the sky, and 
their weather is cooler.
Then, when we're on the other side of the sun, the top pole leans slightly 
away from the sun.  During that time the sun shines more directly on the 
bottom half
of the Earth, and less directly on the top half.  The people on 
the bottom half see the sun higher in the sky, and their weather is warmer,
while the people on the top half see the sun lower in the sky, and their 
weather is cooler.
The Earth makes the complete trip around the sun in one year, so the 
people on the Earth go through this cycle of higher/lower sun and 
warmer/cooler weather every year.