Answer:
a biologic trade of sperm/ semen and egg cells
when these are traded only then reproduction occurs
 
        
             
        
        
        
Answer:
Ozone layer saves the earth from the ultraviolet rays of sun which is harmful for earth. It is situated jn upper atmosphere and saves earth. But thus chlorofluorocarbons destroys the Ozone Layer in the atmosphere.
 
        
             
        
        
        
Coal destroys wildlife hurts communities destroys countryside so its pretty bad
        
                    
             
        
        
        
Each nucleotide only pairs with one nucleotide
        
             
        
        
        
6 m/s
This type of collision is a <u>Inelastic collision </u>
Explanation:
We begin by finding the momentum of the initial train car;
Remember that momentum is given by the formulae mass (kg) * velocity (m/s)
Therefore;
Momentum = 6000 * 10
= 60,000 kg⋅m/s
The other car has zero momentum because;
4000 * 0 
= 0
When the two train cars collide, the total momentum will be;
60,000 + 0 = 60,000
Therefore to find the velocity, well use the same formulae;
p = mv  whereby;
p – momentum
m – mass 
v – velocity
60,000 = (6000 + 4000) * v
v = 60,000 / 10,000
v = 6
= 6 m/s
This is an elastic collision because we are assuming that no energy is lost in the collision. Most collisions, however, are not elastic but rather inelastic. In inelastic collision some of the kinetic energy is lost to the environment in some other form of energy such as heat energy.
Learn More:
For more on elastic collisions check out;
brainly.com/question/10864123
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