Answer: 
v doubles and f is unchanged
Explanation:
According to the formula v = f¶
Where v is the velocity of the wave
f is the frequency
¶ is the wavelength
Velocity is directly proportional to wavelength. Direct proportionality shows that increase in velocity will cause an increase in the wavelength and decrease in velocity will also cause a decrease in wavelength with the frequency not changing since the velocity and wavelength are both increasing and decreasing at the same rate. 
According to the question, if the wavelength is doubled, the velocity (v) will also double while the frequency (f) remains unchanged.
 
        
                    
             
        
        
        
No it does not . That is the answer
        
             
        
        
        
the formula for momentum is velocity times mass
car :
1200 x 30 = 36000
truck:
2000 x 20 = 40000
Ans : truck has a greater momentum
 
        
             
        
        
        
Answer:
2587.2 J.
Explanation:
From potential energy,
The work done to lift the chain = potential energy of the chain.
W = mgh............... Equation 1
Where W = work done to lift the chain, m = mass of the chain, g = acceleration due to gravity of the chain, h = height of the chain.
But,
m = m'd............... Equation 2
Where m' = density of the chain, d = length of the chain.
Substitute equation 2 into equation 1
W = m'dgh................ Equation 3
Given: m' = 2 kg/m, d = 12 m, h = 11 m, g = 9.8 m/s²
Substitute into equation 3
W = 2(12)(11)(9.8)
W = 2587.2 J.
 
        
             
        
        
        
Answer:
The answer is either 5 or I'm learning something different and I just can't read
Explanation:
I hope this helped...