Answer:
This question can be answered by using conversation of energy. 



Explanation:
Note that we take  because we are looking for the minimum initial speed for the penguin to reach the top of the second hill. Any other speed more than this will already be enough for him.
 because we are looking for the minimum initial speed for the penguin to reach the top of the second hill. Any other speed more than this will already be enough for him. 
 
        
             
        
        
        
Hey user!
your answer is here..
correct option is A. steel
we know that sounds travel faster in solid as compared to gas and liquids. in gas the molecules are very loosely packed and there is lot of space between so it takes more time to pass sound from each other. and in liquid, the molecules are closer as compared to gas hence it will be little faster and in solid, the molecules are very tightly packed so it will be the fastest. and among these options, steel is the only solid so the speed of sound in steel will be the fastest.
and note that the closer the molecules are to each other ( tightly packed ) makes the bond also tighter and less time to pass sound.
cheers!!
        
             
        
        
        
Eugene Cernan was not the last, but he was the most recent.
        
                    
             
        
        
        
Answer:
Its initial position was 471 m.
Explanation:
We have,
Final position of the object is 327 m
Displacement of the object is -144 m
It is required to find its initial position. The difference of final and initial position is equal to the displacement of the object. So,

So, its initial position was 471 m.
 
        
             
        
        
        
<span>A red ladybug appears red in white light,red in red light, and black in blue light.</span>