The whole question is talking about the amplitude of a wave 
that's transverse and wiggling vertically.
Equilibrium to the crest . . . that's the amplitude.
Crest to trough . . . that's double the amplitude.
Trough to trough . . . How did that get in here ?  Yes, that's 
                               the wavelength, but it has nothing to do
                               with vertical displacement. 
Frequency . . . that's how many complete waves pass a mark 
                       on the ground every second.  Doesn't belong here.
Notice that this has to be a transverse wave.  If it's a longitudinal wave,
like sound or a slinky, then it may not have any displacement at all
across the direction it's moving. 
It also has to be a vertically 'polarized' wave.  If it's wiggling across 
the direction it's traveling BUT it's wiggling side-to-side, then it has 
no vertical displacement.  It still has an amplitude, but the amplitude 
is all horizontal.
        
             
        
        
        
Answer:
D
Explanation:
In order to disprove an old theory you need to prove a new one that contradicts it using scientific research and experimentation 
 
        
             
        
        
        
Answer:
C) three
Explanation:
Let gram of gold required be m . Let temperature change in both be Δ t . 
heat absorbed = mass x specific heat x change in temperature 
for copper 
heat absorbed = 1 x .385 x Δt 
for gold 
heat absorbed = m x .129 x Δt
So 
m x .129 x Δt = 1 x .385 x Δt
m = 2.98
= 3 g approximately . 
 
        
             
        
        
        
Answer:
CO2 emissions from fossil fuel burning should be minimized at all cost. The CO2 are gotten when the carbons from hydrocarbons react with air(oxygen). This gas erodes the ozone layer which makes the melting of ice caps faster due to increased amount of heat radiations on the earth. This is the only best and permanent solution to the reduction of the amount of heat rays on the earth which is a global problem. 
Objects which reflects back the sunrays could also be inserted into the sea to prevent the melting of the ice caps.