Answer:
32.46m/s
Explanation:
Hello,
To solve this exercise we must be clear that the ball moves with constant acceleration with the value of gravity = 9.81m / S ^ 2
A body that moves with constant acceleration means that it moves in "a uniformly accelerated motion", which means that if the velocity is plotted with respect to time we will find a line and its slope will be the value of the acceleration, it determines how much it changes the speed with respect to time.
When performing a mathematical demonstration, it is found that the equations that define this movement are the follow

Where
Vf = final speed
Vo = Initial speed
=7.3m/S
A = g=acceleration
=9.81m/s^2
X = displacement
=51m}
solving for Vf

the speed with the ball hits the ground is 32.46m/s
Answer:
a

b

Explanation:
From the question we are told that
Their distance apart is 
The wavelength of each source wave 
Let the distance from source A where the construct interference occurred be z
Generally the path difference for constructive interference is

Now given that we are considering just the straight line (i.e points along the line connecting the two sources ) then the order of the maxima m = 0
so

=> 
=> 
Generally the path difference for destructive interference is

=> 
=> 
substituting values

=> 
So


and

=> 
=> 
A change in position with respect to a reference point is called motion
hope it helps...