Answer:
a
all the molecules or atoms in motion has kinetic energy 
 
        
             
        
        
        
Answer: The most likely identity of the substance is iron.
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

Q = Heat absorbed= Joules
 Joules
m= mass of substance = 11.9 g
c = specific heat capacity = ?
Initial temperature of the water =  = 25.0°C
 = 25.0°C
Final temperature of the water =  = 45.0°CChange in temperature ,
  = 45.0°CChange in temperature ,
Putting in the values, we get:


The specific heat of 0.45 is for iron and thus the substance is iron.
 
        
             
        
        
        
D = distance between th two trains at the start of the motion = 100 miles
V = speed of the faster train towards slower train = 60 mph 
v = speed of the slower train towards faster train = 40 mph 
t = time taken by the two trains to collide = ?
 time taken by the two trains to collide is given as 
t = D/(V + v)
t = 100/(60 + 40) = 1 h 
v' = speed of the bird = 90 mph 
d = distance traveled by the bird
distance traveled by the bird is given as 
d = v' t 
d = 90 x 1 
d = 90 miles 
 
        
                    
             
        
        
        
Answer:
 The maximum kinetic energy is 100 j.      
Explanation:
<h3>The kinetic energy = (potential energy) + (kinetic energy) and the potential energy of 0 J implying its kinetic energy is 100 J, which is its maximum.
</h3>
 
        
                    
             
        
        
        
Answer:
a=2 ok do it and ........