Frequency is measured in units of reciprocal time.
Period is measured in units of time.
Phase is a number without units that represents a fraction of a wave.
None of these is measured in meters, so none of them can be the answer.
It must be either amplitude or wavelength.
Amplitude is a quantity that's measured at one or two points in the same wave.
The question is talking about points on consecutive waves.
<em>Wavelength is</em> the only choice left.  That must be it.
        
                    
             
        
        
        
What is a travelling wave and a standing wave? What are the differences between both of them?
Answer: First of all we have to understand that a traveling wave is an organized disturbance traveling with a well defined wave speed. On the other hand standing waves are the combination of period waves with their reflected waves creating double sided waves. The differences between them is that standing waves have nodes and antinodes while a traveling wave does not.
I hope it helps, Regards.
        
                    
             
        
        
        
The correct answer to the question is : A) The velocity of the cart after it hits the wall.
EXPLANATION:
Before answering this question, first we have to understand impulse.
Impulse of a body is defined as the change in momentum or the product of force with time.
Mathematically impulse = m ( v- u ).
Here, v is the final momentum and u is the initial momentum.
Hence, we need the velocity of the cart after it hits the wall in order to calculate the impulse of the lab cart.
 
        
                    
             
        
        
        
I think it's a pulley and a lever.