Kinetic energy = (1/2) (mass) (speed²).
A Physicist in the canoe, or on a raft floating downriver next to the canoe, will say that the canoe's kinetic energy is zero.
A Physicist on the riverbank, watching the canoe drift by at 1 m/s, will say that its kinetic energy is 9 Joules.
They're both correct.
 
        
             
        
        
        
Answer:
A. The waves in the water travel faster and at a higher frequency than they travel on land.
Explanation:
The main reason why human ears can hear dolphins' vocalizations while under the water but cannot hear them well on land is because water is denser than air and air particles travel faster in denser particles.
Denser particles also ensures that the frequency of the waves move faster which in turn produces a faster and louder result.
 
        
             
        
        
        
Answer:
The length of open-open pipe needed is 6.23 m
The length of open-close  pipe needed is 3.11 m
Explanation:
Fundamental frequency for standing wave mode of  an open- open pipe is given by
 
where v is the velocity and L is the length
The length of open-open pipe needed is

Fundamental frequency for standing wave mode of  an open- close pipe is given by
 
The length of open-close pipe needed is

 
        
             
        
        
        
Answer:
As indicated by Newton's law of attraction each article or body in the universe draws in every single item towards one another and that power of fascination is straightforwardly relative to the result of their masses and contrarily corresponding to the square of the distance between them.  
The power of gravity between two articles will diminish as the distance between them increments. The two most significant elements influencing the gravitational power between two items are their mass and the distance between their focuses. As mass increments, so does the power of gravity, however an increment in distance mirrors a reverse proportionality, which makes that power decline dramatically.  
At that point by Newton's All inclusive Law of Attractive energy;  
F=GMm/R^2  
Mm= result of the majority  
R=Distance Between the two masses by focus.  
On the off chance that R is multiplied, new force=GMm/(2R)^2  
=GMm/4R^2  
Unique Power/New Force=4/1  
F/4=New Power