Explanation:
Work done by gravity is given by the formula,
W =
......... (1)
It is known that when levels are same then height of the liquid is as follows.
h =
......... (2)
Putting value of equation (2) in equation (1) the overall formula will be as follows.
W = 
= 
= 0.689 J
Thus, we can conclude that the work done by the gravitational force in equalizing the levels when the two vessels are connected is 0.689 J.
Refraction is
the bending of the waves which is result of the fact that different parts of
the wave reach the water with different speeds because of the angle approaching
the shore.
<span>The
wave refraction disperses the wave energy in quiet water areas and sand is
deposited.<span> </span></span>
a)
Y₀ = initial position of the stone at the time of launch = 0 m
Y = final position of stone = 20.0 meters
a = acceleration = - 9.8 m/s²
v₀ = initial speed of stone at the time of launch = 30.0 m/s
v = final speed = ?
Using the equation
v² = v₀² + 2 a (Y - Y₀)
inserting the values
v² = 30² + 2 (- 9.8) (20 - 0)
v = 22.5 m/s
b)
Y₀ = initial position of the stone at the time of launch = 0 m
Y = maximum height gained
a = acceleration = - 9.8 m/s²
v₀ = initial speed of stone at the time of launch = 30.0 m/s
v = final speed = 0 m/s
Using the equation
v² = v₀² + 2 a (Y - Y₀)
inserting the values
0² = 30² + 2 (- 9.8) (Y - 0)
Y = 46 m
Gravitational potential energy i think